drm/nvc0: enable protection of system-use-only structures in vm

Somehow missed this in the original merge of the nvc0 code.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nvc0_graph.c b/drivers/gpu/drm/nouveau/nvc0_graph.c
index 5feacd5..e6ea7d8 100644
--- a/drivers/gpu/drm/nouveau/nvc0_graph.c
+++ b/drivers/gpu/drm/nouveau/nvc0_graph.c
@@ -105,7 +105,8 @@
 	if (ret)
 		return ret;
 
-	ret = nouveau_gpuobj_new(dev, NULL, 384 * 1024, 4096, NVOBJ_FLAG_VM,
+	ret = nouveau_gpuobj_new(dev, NULL, 384 * 1024, 4096,
+				 NVOBJ_FLAG_VM | NVOBJ_FLAG_VM_USER,
 				 &grch->unk418810);
 	if (ret)
 		return ret;