arm64: dts: qcom: sm6375: Add GPUCC and Adreno SMMU

Add GPUCC and Adreno SMMU nodes in preparation for adding the GPU
itself.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230531-topic-sm6375_gpusmmu-v1-2-860943894c71@linaro.org