drm/i915: use DPLL_DVO_HIGH_SPEED for PCH eDP

As with other PCH DP connections.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5f00632..acd7180 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3850,7 +3850,7 @@
 			}
 			dpll |= DPLL_DVO_HIGH_SPEED;
 		}
-		if (is_dp)
+		if (is_dp || intel_encoder_is_pch_edp(&has_edp_encoder->base))
 			dpll |= DPLL_DVO_HIGH_SPEED;
 
 		/* compute bitmask from p1 value */