drm/i915/cnl: Cannonlake color init.

Cannonlake has same color setup as Geminilake.
Legacy color load luts doesn't work anymore on Cannonlake+.

Cc: Clint Taylor <clinton.a.taylor@intel.com>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Clinton Taylor <clinton.a.taylor@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1499374873-2454-1-git-send-email-rodrigo.vivi@intel.com