arm64: dts: qcom: sdm630: Add MMCC node

Add MultiMedia Clock Controller node to allow for accessing
and controlling Multimedia Subsystem clocks by their respective
users.

Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Link: https://lore.kernel.org/r/20210728222542.54269-4-konrad.dybcio@somainline.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>