drm/i915: Remove ckey/format checks from skl_update_scaler_plane()

skl_plane_check() already takes care to reject scaling when an
unsupported pixel format or color keying is used. No need to
replicate that in the scaler code.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241016143134.26903-10-ville.syrjala@linux.intel.com


Reviewed-by: Jani Nikula <jani.nikula@intel.com>