drm/i915: Remove unused dev_priv->panel_wants_dither

This is now private to the DVO connector, remove it from the main device
private.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index e1f6e05..1317731 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -229,7 +229,7 @@
 
 	/* Make sure pre-965s set dither correctly */
 	if (INTEL_INFO(dev)->gen < 4) {
-		if (dev_priv->panel_wants_dither || dev_priv->lvds_dither)
+		if (dev_priv->lvds_dither)
 			pfit_control |= PANEL_8TO6_DITHER_ENABLE;
 	}