LEDs connected to Spreadtrum SC27XX PMIC breathing light controller

The SC27xx breathing light controller supports to 3 outputs:
red LED, green LED and blue LED. Each LED can work at normal
PWM mode or breath light mode.

Required properties:
- compatible: Should be "sprd,sc2731-bltc".
- #address-cells: Must be 1.
- #size-cells: Must be 0.
- reg: Specify the controller address.

Required child properties:
- reg: Port this LED is connected to.

Optional child properties:
- function: See Documentation/devicetree/bindings/leds/common.txt.
- color: See Documentation/devicetree/bindings/leds/common.txt.
- label: See Documentation/devicetree/bindings/leds/common.txt (deprecated).

Examples:

led-controller@200 {
	compatible = "sprd,sc2731-bltc";
	#address-cells = <1>;
	#size-cells = <0>;
	reg = <0x200>;

	led@0 {
		color = <LED_COLOR_ID_RED>;
		reg = <0x0>;
	};

	led@1 {
		color = <LED_COLOR_ID_GREEN>;
		reg = <0x1>;
	};

	led@2 {
		color = <LED_COLOR_ID_BLUE>;
		reg = <0x2>;
	};
};
