i915: Reject CCS modifiers for pipe C on Geminilake

Current code advertises (on the modifiers blob property) support for CCS
modifier for pipe C on GLK, only to reject it later when validating the
request before the atomic commit.

This fixes the tests igt@kms_ccs@pipe-c-*, which should skip on GLK for
pipe C (see bug 104096).

A relevant discussion is archived at:

https://lists.freedesktop.org/archives/intel-gfx/2017-December/150646.html

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104096
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Cc: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171220002410.5604-1-krisman@collabora.co.uk

drivers/gpu/drm/i915/intel_display.c

@@ -13263,7 +13263,7 @@ intel_primary_plane_create(struct drm_i915_private *dev_priv, enum pipe pipe)
 	primary->frontbuffer_bit = INTEL_FRONTBUFFER_PRIMARY(pipe);
 	primary->check_plane = intel_check_primary_plane;
 
-	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)) {
+	if (INTEL_GEN(dev_priv) >= 10) {
 		intel_primary_formats = skl_primary_formats;
 		num_formats = ARRAY_SIZE(skl_primary_formats);
 		modifiers = skl_format_modifiers_ccs;