drm/i915: Define skl+ palette anti-collision bit

I've been frobbing the palette anti-collision logic bit
while playing around with DSB. Not sure we'll have real
use for this but let's define the bit anyways so I don't
have to carry it around locally.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221123152638.20622-4-ville.syrjala@linux.intel.com


Reviewed-by: Uma Shankar <uma.shankar@intel.com>