Add support for the display clock controller found in SM8550
based devices.

This clock controller feeds the Multimedia Display SubSystem (MDSS).
This driver is based on the SM8450 support.
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230103-topic-sm8550-upstream-dispcc-v3-3-8a03d348c572@linaro.org