In the DP driver, check if VSC SDP is supported and propagate this value
to dp_panel. In dp_display's dp_mode, the out_fmt_is_yuv_420 parameter
must also utilize this value since YUV420 is only allowed when VSC SDP
is supported.

Changes in v2:
	- Move DP programming when VSC SDP is supported to this patch
Signed-off-by: Paloma Arellano <quic_parellan@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/579625/
Link: https://lore.kernel.org/r/20240222194025.25329-9-quic_parellan@quicinc.comSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>