drm/i915/cnl: Extend HDMI 2.0 support to CNL.

Starting on GLK we support HDMI 2.0. So this patch only
extend the work Shashank has made to GLK to CNL.

v2: The version that compiles :/
v3: Invert order to newer || older platforms check. (Ville).

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171115184205.8104-1-rodrigo.vivi@intel.com

drivers/gpu/drm/i915/intel_hdmi.c

@@ -1235,7 +1235,7 @@ static int intel_hdmi_source_max_tmds_clock(struct intel_encoder *encoder)
 		&dev_priv->vbt.ddi_port_info[encoder->port];
 	int max_tmds_clock;
 
-	if (IS_GEMINILAKE(dev_priv))
+	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
 		max_tmds_clock = 594000;
 	else if (INTEL_GEN(dev_priv) >= 8 || IS_HASWELL(dev_priv))
 		max_tmds_clock = 300000;
@@ -1511,7 +1511,8 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 
 	pipe_config->lane_count = 4;
 
-	if (scdc->scrambling.supported && IS_GEMINILAKE(dev_priv)) {
+	if (scdc->scrambling.supported && (INTEL_GEN(dev_priv) >= 10 ||
+					   IS_GEMINILAKE(dev_priv))) {
 		if (scdc->scrambling.low_rates)
 			pipe_config->hdmi_scrambling = true;
 
@@ -2033,7 +2034,7 @@ 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))
+	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
 		connector->ycbcr_420_allowed = true;
 
 	intel_hdmi->ddc_bus = intel_hdmi_ddc_pin(dev_priv, port);