arm64: dts: qcom: sm8150: Add DISPCC node

Years after the SoC support has been added, it's high time for it to
get dispcc going. Add the node to ensure that.

Tested-by: Marijn Suijten <marijn.suijten@somainline.org> # Xperia 5
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221229100511.979972-2-konrad.dybcio@linaro.org