ARM: dts: sun6i: hummingbird: Add AXP221 PMIC device node

The Hummingbird A31 has an AXP221 PMIC hooked up to the
P2WI controller.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun6i-a31-hummingbird.dts

@@ -142,6 +142,15 @@ mmc0_cd_pin_hummingbird: mmc0_cd_pin@0 {
 
 &p2wi {
 	status = "okay";
+
+	axp221: pmic@68 {
+		compatible = "x-powers,axp221";
+		reg = <0x68>;
+		interrupt-parent = <&nmi_intc>;
+		interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
+		interrupt-controller;
+		#interrupt-cells = <1>;
+	};
 };
 
 &reg_usb1_vbus {