dt-bindings: mfd: regulator: Drop BD70528 support

The only known BD70528 use-cases are such that the PMIC is controlled
from separate MCU which is not running Linux. I am not aware of
any Linux driver users. Furthermore, it seems there is no demand for
this IC. Let's ease the maintenance burden and drop the driver. We can
always add it back if there is sudden need for it.
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/64c88990270d9a22508446ef2fe3b6a2622a0b01.1637066805.git.matti.vaittinen@fi.rohmeurope.com

Documentation/devicetree/bindings/mfd/rohm,bd70528-pmic.txt

-* ROHM BD70528 Power Management Integrated Circuit bindings
-
-BD70528MWV is an ultra-low quiescent current general purpose, single-chip,
-power management IC for battery-powered portable devices. The IC
-integrates 3 ultra-low current consumption buck converters, 3 LDOs and 2
-LED Drivers. Also included are 4 GPIOs, a real-time clock (RTC), a 32kHz
-clock gate, high-accuracy VREF for use with an external ADC, flexible
-dual-input power path, 10 bit SAR ADC for battery temperature monitor and
-1S battery charger with scalable charge currents.
-
-Required properties:
- - compatible		: Should be "rohm,bd70528"
- - reg			: I2C slave address.
- - interrupts		: The interrupt line the device is connected to.
- - interrupt-controller	: To indicate BD70528 acts as an interrupt controller.
- - #interrupt-cells	: Should be 2. Usage is compliant to the 2 cells
-			  variant of ../interrupt-controller/interrupts.txt
- - gpio-controller	: To indicate BD70528 acts as a GPIO controller.
- - #gpio-cells		: Should be 2. The first cell is the pin number and
-			  the second cell is used to specify flags. See
-			  ../gpio/gpio.txt for more information.
- - #clock-cells		: Should be 0.
- - regulators:		: List of child nodes that specify the regulators.
-			  Please see ../regulator/rohm,bd70528-regulator.txt
-
-Optional properties:
- - clock-output-names	: Should contain name for output clock.
-
-Example:
-/* External oscillator */
-osc: oscillator {
-	compatible = "fixed-clock";
-	#clock-cells = <1>;
-	clock-frequency  = <32768>;
-	clock-output-names = "osc";
-};
-
-pmic: pmic@4b {
-	compatible = "rohm,bd70528";
-	reg = <0x4b>;
-	interrupt-parent = <&gpio1>;
-	interrupts = <29 IRQ_TYPE_LEVEL_LOW>;
-	clocks = <&osc 0>;
-	#clock-cells = <0>;
-	clock-output-names = "bd70528-32k-out";
-	#gpio-cells = <2>;
-	gpio-controller;
-	interrupt-controller;
-	#interrupt-cells = <2>;
-
-	regulators {
-		buck1: BUCK1 {
-			regulator-name = "buck1";
-			regulator-min-microvolt = <1200000>;
-			regulator-max-microvolt = <3400000>;
-			regulator-boot-on;
-			regulator-ramp-delay = <125>;
-		};
-		buck2: BUCK2 {
-			regulator-name = "buck2";
-			regulator-min-microvolt = <1200000>;
-			regulator-max-microvolt = <3300000>;
-			regulator-boot-on;
-			regulator-ramp-delay = <125>;
-		};
-		buck3: BUCK3 {
-			regulator-name = "buck3";
-			regulator-min-microvolt = <800000>;
-			regulator-max-microvolt = <1800000>;
-			regulator-boot-on;
-			regulator-ramp-delay = <250>;
-		};
-		ldo1: LDO1 {
-			regulator-name = "ldo1";
-			regulator-min-microvolt = <1650000>;
-			regulator-max-microvolt = <3300000>;
-			regulator-boot-on;
-		};
-		ldo2: LDO2 {
-			regulator-name = "ldo2";
-			regulator-min-microvolt = <1650000>;
-			regulator-max-microvolt = <3300000>;
-			regulator-boot-on;
-		};
-
-		ldo3: LDO3 {
-			regulator-name = "ldo3";
-			regulator-min-microvolt = <1650000>;
-			regulator-max-microvolt = <3300000>;
-		};
-		led_ldo1: LED_LDO1 {
-			regulator-name = "led_ldo1";
-			regulator-min-microvolt = <200000>;
-			regulator-max-microvolt = <300000>;
-		};
-		led_ldo2: LED_LDO2 {
-			regulator-name = "led_ldo2";
-			regulator-min-microvolt = <200000>;
-			regulator-max-microvolt = <300000>;
-		};
-	};
-};

Documentation/devicetree/bindings/regulator/rohm,bd70528-regulator.txt

-ROHM BD70528 Power Management Integrated Circuit regulator bindings
-
-Required properties:
- - regulator-name: should be "buck1", "buck2", "buck3", "ldo1", "ldo2", "ldo3",
-		   "led_ldo1", "led_ldo2"
-
-List of regulators provided by this controller. BD70528 regulators node
-should be sub node of the BD70528 MFD node. See BD70528 MFD bindings at
-Documentation/devicetree/bindings/mfd/rohm,bd70528-pmic.txt
-
-The valid names for BD70528 regulator nodes are:
-BUCK1, BUCK2, BUCK3, LDO1, LDO2, LDO3, LED_LDO1, LED_LDO2
-
-Optional properties:
-- Any optional property defined in bindings/regulator/regulator.txt
-
-Example:
-regulators {
-	buck1: BUCK1 {
-		regulator-name = "buck1";
-		regulator-min-microvolt = <1200000>;
-		regulator-max-microvolt = <3400000>;
-		regulator-boot-on;
-		regulator-ramp-delay = <125>;
-	};
-	buck2: BUCK2 {
-		regulator-name = "buck2";
-		regulator-min-microvolt = <1200000>;
-		regulator-max-microvolt = <3300000>;
-		regulator-boot-on;
-		regulator-ramp-delay = <125>;
-	};
-	buck3: BUCK3 {
-		regulator-name = "buck3";
-		regulator-min-microvolt = <800000>;
-		regulator-max-microvolt = <1800000>;
-		regulator-boot-on;
-		regulator-ramp-delay = <250>;
-	};
-	ldo1: LDO1 {
-		regulator-name = "ldo1";
-		regulator-min-microvolt = <1650000>;
-		regulator-max-microvolt = <3300000>;
-		regulator-boot-on;
-	};
-	ldo2: LDO2 {
-		regulator-name = "ldo2";
-		regulator-min-microvolt = <1650000>;
-		regulator-max-microvolt = <3300000>;
-		regulator-boot-on;
-	};
-
-	ldo3: LDO3 {
-		regulator-name = "ldo3";
-		regulator-min-microvolt = <1650000>;
-		regulator-max-microvolt = <3300000>;
-	};
-	led_ldo1: LED_LDO1 {
-		regulator-name = "led_ldo1";
-		regulator-min-microvolt = <200000>;
-		regulator-max-microvolt = <300000>;
-	};
-	led_ldo2: LED_LDO2 {
-		regulator-name = "led_ldo2";
-		regulator-min-microvolt = <200000>;
-		regulator-max-microvolt = <300000>;
-	};
-};