arm64: dts: rockchip: enable the GPU for RK3399-GRU

This patch enables the gpu and adds the mali-supply power for RK3399-GRU
devices.
Signed-off-by: NCaesar Wang <wxt@rock-chips.com>
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi

@@ -595,6 +595,11 @@
 	status = "okay";
 };
 
+&gpu {
+	mali-supply = <&ppvar_gpu>;
+	status = "okay";
+};
+
 ap_i2c_mic: &i2c1 {
 	status = "okay";