drm/i915: release scratch page at module unload

Signed-off-by: NImre Deak <imre.deak@intel.com>
Acked-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_dma.c

@@ -1790,6 +1790,8 @@ int i915_driver_unload(struct drm_device *dev)
 	destroy_workqueue(dev_priv->wq);
 	pm_qos_remove_request(&dev_priv->pm_qos);
 
+	dev_priv->gtt.gtt_remove(dev);
+
 	if (dev_priv->slab)
 		kmem_cache_destroy(dev_priv->slab);