drm/nv50-/disp: use self as parent for subobjects

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c b/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
index 6088344..6a38402 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
@@ -572,7 +572,8 @@
 	priv->base.vblank->priv = priv;
 	priv->base.vblank->enable = nv50_disp_base_vblank_enable;
 	priv->base.vblank->disable = nv50_disp_base_vblank_disable;
-	return nouveau_ramht_new(parent, parent, 0x1000, 0, &base->ramht);
+	return nouveau_ramht_new(nv_object(base), nv_object(base), 0x1000, 0,
+				&base->ramht);
 }
 
 static void