drm/i915/glk: Program pipe gamma and degamma tables

The gamma tables in Geminilake were changed. There is no split-gamma
mode. Instead, there is a dedicated degamma table that is enabled
whenever pipe CSC is enabled.

The dedicated gamma table has 16 bit precision but doesn't support
separate channels. Since that doesn't match the per-channel format of
the degamma LUT property, for now only a linear table is loaded and the
property ignored.

v2: Remove empty line. (Ville)
    Reuse broadwell code. (Ville)

v3: Don't write PIPE_CSC_MODE. (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170127090230.20302-1-ander.conselvan.de.oliveira@intel.com
diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
index ecb487b..df2051b 100644
--- a/drivers/gpu/drm/i915/i915_pci.c
+++ b/drivers/gpu/drm/i915/i915_pci.c
@@ -403,6 +403,7 @@ static const struct intel_device_info intel_geminilake_info = {
 	.platform = INTEL_GEMINILAKE,
 	.is_alpha_support = 1,
 	.ddb_size = 1024,
+	.color = { .degamma_lut_size = 0, .gamma_lut_size = 1024 }
 };
 
 static const struct intel_device_info intel_kabylake_info = {