drm/i915: embed the gem object into drm_i915_gem_object

Just embed it and adjust the pointers, No other changes (that's
for later patches).

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6b931b8..d1b7dec 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -647,6 +647,7 @@
 
 /** driver private structure attached to each drm_gem_object */
 struct drm_i915_gem_object {
+	struct drm_gem_object base;
 	struct drm_gem_object *obj;
 
 	/** Current space allocated to this object in the GTT, if any. */