drm/i915/xelpd: Enable Pipe Degamma

drm/i915/xelpd: Enable Pipe Degamma

BugLink: https://bugs.launchpad.net/bugs/1967274
Enable Pipe Degamma for XE_LPD. Extend the legacy implementation
to incorparate the extended lut size for XE_LPD.

v2: Added a helper for degamma lut size (Ville)

Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211207071135.3660332-3-uma.shankar@intel.com
(cherry picked from commit 17815f624a90579aeac4b700f8434e9ff6a6d001)
Signed-off-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>