drm/msm/dp: allow YUV420 mode for DP connector when CDM available

All the components of YUV420 over DP are added. Therefore, let's mark the
connector property as true for DP connector when the DP type is not eDP
and when there is a CDM block available.

Changes in v3:
	- Move setting the connector's ycbcr_420_allowed parameter so
	  that it is not dependent on if the dp_display is not eDP

Changes in v2:
	- Check for if dp_catalog has a CDM block available instead of
	  checking if VSC SDP is allowed when setting the dp connector's
	  ycbcr_420_allowed parameter

Signed-off-by: Paloma Arellano <quic_parellan@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/579628/
Link: https://lore.kernel.org/r/20240222194025.25329-20-quic_parellan@quicinc.com


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