arm64: dts: qcom: msm8996: Make GPU node control GPU_GX GDSC

Presumably the GPU node needs to control both the GPU and GPU GX power
domains, but given that GPU GX now depends on the GPU GDSC both can
effectively be controlled by controlling GPU GX. So use this instead.
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20200417070044.1376212-5-bjorn.andersson@linaro.orgSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

arch/arm64/boot/dts/qcom/msm8996.dtsi

@@ -639,7 +639,7 @@ gpu@b00000 {
 				"mem",
 				"mem_iface";
 
-			power-domains = <&mmcc GPU_GDSC>;
+			power-domains = <&mmcc GPU_GX_GDSC>;
 			iommus = <&adreno_smmu 0>;
 
 			nvmem-cells = <&gpu_speed_bin>;