drm/i915: Sprinke a few sanity check WARNS during csc assignment

Make sure the csc enable bit(s) match the way we're about to
fill the csc matrices.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230329135002.3096-8-ville.syrjala@linux.intel.com


Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>