ARM: sunxi: Add fixed 3V regulator

A few boards we've seen have a fixed 3V regulator. Add this one on the common
DTSI.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

arch/arm/boot/dts/sunxi-common-regulators.dtsi

@@ -73,6 +73,13 @@ reg_usb2_vbus: usb2-vbus {
 		status = "disabled";
 	};
 
+	reg_vcc3v0: vcc3v0 {
+		compatible = "regulator-fixed";
+		regulator-name = "vcc3v0";
+		regulator-min-microvolt = <3000000>;
+		regulator-max-microvolt = <3000000>;
+	};
+
 	reg_vcc3v3: vcc3v3 {
 		compatible = "regulator-fixed";
 		regulator-name = "vcc3v3";