drm/msm/dp: program config ctrl for YUV420 over DP

Change relevant DP controller related programming for YUV420 cases.
Program the configuration control register to indicate YUV420.

Changes in v2:
	- Create a new patch only for configuration control programming

Signed-off-by: Paloma Arellano <quic_parellan@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/579615/
Link: https://lore.kernel.org/r/20240222194025.25329-11-quic_parellan@quicinc.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>