ARM: dts: sun7i: Add regulator configuration for pcDuino v3 Nano

The power configuration on this board is the same as the pcDuino v3.
This will enable frequency/voltage scaling over the standard A20
operating points from 144 MHz to 960 MHz.

Tested using cpufreq-ljt-stress-test on two pcDuino v3 Nano boards; also
tested successfully with voltages reduced by 0.025 V.
Signed-off-by: Adam Sampson <ats@offog.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun7i-a20-pcduino3-nano.dts

@@ -82,6 +82,10 @@ &ahci {
 	status = "okay";
 };
 
+&cpu0 {
+	cpu-supply = <&reg_dcdc2>;
+};
+
 &ehci0 {
 	status = "okay";
 };
@@ -108,13 +112,9 @@ &i2c0 {
 	status = "okay";
 
 	axp209: pmic@34 {
-		compatible = "x-powers,axp209";
 		reg = <0x34>;
 		interrupt-parent = <&nmi_intc>;
 		interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
-
-		interrupt-controller;
-		#interrupt-cells = <1>;
 	};
 };
 
@@ -171,6 +171,33 @@ &reg_ahci_5v {
 	status = "okay";
 };
 
+#include "axp209.dtsi"
+
+&reg_dcdc2 {
+	regulator-always-on;
+	regulator-min-microvolt = <1000000>;
+	regulator-max-microvolt = <1400000>;
+	regulator-name = "vdd-cpu";
+};
+
+&reg_dcdc3 {
+	regulator-always-on;
+	regulator-min-microvolt = <1000000>;
+	regulator-max-microvolt = <1400000>;
+	regulator-name = "vdd-int-pll";
+};
+
+&reg_ldo1 {
+	regulator-name = "vdd-rtc";
+};
+
+&reg_ldo2 {
+	regulator-always-on;
+	regulator-min-microvolt = <3000000>;
+	regulator-max-microvolt = <3000000>;
+	regulator-name = "avcc";
+};
+
 /* A single regulator (U24) powers both USB host ports. */
 &reg_usb1_vbus {
 	pinctrl-0 = <&usb1_vbus_pin_pcduino3_nano>;