drm/i915: Remove double wait_for_vblank on broadwell.

wait_vblank is already set in intel_plane_atomic_calc_changes
for broadwell, waiting for a double vblank is overkill.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447945645-32005-5-git-send-email-maarten.lankhorst@linux.intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -4708,14 +4708,6 @@ intel_post_enable_primary(struct drm_crtc *crtc)
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	int pipe = intel_crtc->pipe;
 
-	/*
-	 * BDW signals flip done immediately if the plane
-	 * is disabled, even if the plane enable is already
-	 * armed to occur at the next vblank :(
-	 */
-	if (IS_BROADWELL(dev))
-		intel_wait_for_vblank(dev, pipe);
-
 	/*
 	 * FIXME IPS should be fine as long as one plane is
 	 * enabled, but in practice it seems to have problems