ARM: dts: sun7i: enable battery power supply subnode on cubietruck

The Cubietruck has an AXP209 PMIC with battery connector.

This enables the battery power supply subnode.
Signed-off-by: NAlexander Syring <alex@asyring.de>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
[wens@csie.org: Correct subject prefix order]
Signed-off-by: NChen-Yu Tsai <wens@csie.org>

arch/arm/boot/dts/sun7i-a20-cubietruck.dts

@@ -271,6 +271,10 @@
 	status = "okay";
 };
 
+&battery_power_supply {
+	status = "okay";
+};
+
 &reg_dcdc2 {
 	regulator-always-on;
 	regulator-min-microvolt = <1000000>;