drm/dp_helper: Add helper to check DSC support with given o/p format

Add helper to check if the DP sink supports DSC with the given
o/p format.

v2: Add documentation for the helper. (Uma Shankar)

v3: /** instead of  /* (Uma Shankar)

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230309062855.393087-2-suraj.kandpal@intel.com