ARM: dts: vf-colibri: add basic supply regulators

Colibri modules need to be powered using the power pins 3V3 and
AVDD_AUDIO. Add fixed regulators which represent this power rails.
Potentially, those power rails could be switched on a carrier
board. A carrier board device tree could add a own regulator with
a GPIO, and reference that regulator in a vin-supply property of
those new module level system regulators.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/vf-colibri.dtsi

@@ -48,14 +48,30 @@ bl: backlight {
 		enable-gpios = <&gpio1 13 GPIO_ACTIVE_HIGH>;
 		status = "disabled";
 	};
+
+	reg_module_3v3: regulator-module-3v3 {
+		compatible = "regulator-fixed";
+		regulator-name = "+V3.3";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	reg_module_3v3_avdd: regulator-module-3v3-avdd {
+		compatible = "regulator-fixed";
+		regulator-name = "+V3.3_AVDD_AUDIO";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+	};
 };
 
 &adc0 {
 	status = "okay";
+	vref-supply = <&reg_module_3v3_avdd>;
 };
 
 &adc1 {
 	status = "okay";
+	vref-supply = <&reg_module_3v3_avdd>;
 };
 
 &can0 {
@@ -96,6 +112,7 @@ &esdhc1 {
 
 &fec1 {
 	phy-mode = "rmii";
+	phy-supply = <&reg_module_3v3>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_fec1>;
 };