drv/i915: Pull display_clock_mode out of VBT table

This tells the driver whether a CK505 clock source is available on
pre-PCH hardware. If so, it should be used as the non-SSC source,
leaving the internal clock for use as the SSC source.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Chris Wison <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index dcbc839..eb58784 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -309,11 +309,13 @@
 		dev_priv->lvds_use_ssc = general->enable_ssc;
 		dev_priv->lvds_ssc_freq =
 			intel_bios_ssc_frequency(dev, general->ssc_freq);
-		DRM_DEBUG_KMS("BDB_GENERAL_FEATURES int_tv_support %d int_crt_support %d lvds_use_ssc %d lvds_ssc_freq %d\n",
+		dev_priv->display_clock_mode = general->display_clock_mode;
+		DRM_DEBUG_KMS("BDB_GENERAL_FEATURES int_tv_support %d int_crt_support %d lvds_use_ssc %d lvds_ssc_freq %d display_clock_mode %d\n",
 			      dev_priv->int_tv_support,
 			      dev_priv->int_crt_support,
 			      dev_priv->lvds_use_ssc,
-			      dev_priv->lvds_ssc_freq);
+			      dev_priv->lvds_ssc_freq,
+			      dev_priv->display_clock_mode);
 	}
 }