drm/i915/glk: set HDMI 2.0 identifier

This patch sets the is_hdmi2_src identifier in drm connector
for GLK platform. GLK contains a native HDMI 2.0 controller.
This identifier will help the EDID handling functions to save
lot of work which is specific to HDMI 2.0 sources.

V3: Added this patch
V4: Rebase
V4: Rebase
V5: Added r-b from Ander
V6: Rebase
V7: Rebase
V8: Rebase
V9: Added r-b from Ville
V9: Added r-b from Imre

Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Cc: Imre Deak <imre.deak@intel.com>

Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Reviewed-by: Ville Syrjala <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1500650709-14447-7-git-send-email-shashank.sharma@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_hdmi.c

@@ -1917,6 +1917,9 @@ void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
 	connector->doublescan_allowed = 0;
 	connector->stereo_allowed = 1;
 
+	if (IS_GEMINILAKE(dev_priv))
+		connector->ycbcr_420_allowed = true;
+
 	intel_hdmi->ddc_bus = intel_hdmi_ddc_pin(dev_priv, port);
 
 	switch (port) {