ARM: dts: am437x: cm-t43: add spi-flash support

CM-T43 has an on-board 2MB SPI-flash which stores U-Boot and the U-Boot
environment. Add it to the device tree.
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Benoit Cousson <bcousson@baylibre.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Cc: Dmitry Lifshitz <lifshitz@compulab.co.il>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am437x-cm-t43.dts

@@ -44,6 +44,15 @@ AM4372_IOPAD(0x988, PIN_INPUT_PULLUP | SLEWCTRL_FAST | MUX_MODE0)  /* i2c0_sda.i
 			AM4372_IOPAD(0x98c, PIN_INPUT_PULLUP | SLEWCTRL_FAST | MUX_MODE0)  /* i2c0_scl.i2c0_scl */
 		>;
 	};
+
+	spi0_pins: pinmux_spi0_pins {
+		pinctrl-single,pins = <
+			AM4372_IOPAD(0x950, PIN_INPUT | MUX_MODE0) /* spi0_sclk.spi0_sclk */
+			AM4372_IOPAD(0x954, PIN_INPUT | MUX_MODE0) /* spi0_d0.spi0_d0 */
+			AM4372_IOPAD(0x958, PIN_OUTPUT | MUX_MODE0) /* spi0_d1.spi0_d1 */
+			AM4372_IOPAD(0x95C, PIN_OUTPUT | MUX_MODE0) /* spi0_cs0.spi0_cs0 */
+		>;
+	};
 };
 
 &i2c0 {
@@ -146,6 +155,37 @@ &gpio5 {
 	status = "okay";
 };
 
+&spi0 {
+	status = "okay";
+	pinctrl-names = "default";
+	pinctrl-0 = <&spi0_pins>;
+	dmas = <&edma 16
+		&edma 17>;
+	dma-names = "tx0", "rx0";
+
+	flash: w25q64cvzpig@0 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <20000000>;
+		partition@0 {
+			label = "uboot";
+			reg = <0x0 0xc0000>;
+		};
+
+		partition@c0000 {
+			label = "uboot environment";
+			reg = <0xc0000 0x40000>;
+		};
+
+		partition@100000 {
+			label = "reserved";
+			reg = <0x100000 0x100000>;
+		};
+	};
+};
+
 &uart0 {
 	status = "okay";
 };