drm/i915/icl: Don't set pipe CSC/Gamma in PLANE_COLOR_CTL

These fields have been deprecated and moved in ICL+. Stop setting the
bits.

They have moved to GAMMA_MODE and CSC_MODE, respectively. This patch
is just to stop incorrectly setting bits in PLANE_COLOR_CTL while
we're waiting for the new replacement functionality to be done.

v2: Drop useless comment, and change !(GEN >= 11) to (GEN < 11). (Ville)

v3: No changes

v4 (from Paulo): Rebase.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: James Ausmus <james.ausmus@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328215803.13835-2-paulo.r.zanoni@intel.com