drm/i915/gtt: Clear the cachelines upon resume

Required for my pineview system to not barf after resuming.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 71c2b0f..86673e7 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -35,6 +35,8 @@
 	struct drm_i915_gem_object *obj;
 
 	list_for_each_entry(obj, &dev_priv->mm.gtt_list, gtt_list) {
+		i915_gem_clflush_object(obj);
+
 		if (dev_priv->mm.gtt->needs_dmar) {
 			BUG_ON(!obj->sg_list);
 
@@ -51,7 +53,6 @@
 					       obj->agp_type);
 	}
 
-	/* Be paranoid and flush the chipset cache. */
 	intel_gtt_chipset_flush();
 }