drm/nouveau: replace nv04_graph_fifo_access() use with direct reg bashing

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nv20_graph.c b/drivers/gpu/drm/nouveau/nv20_graph.c
index f873627..3791222 100644
--- a/drivers/gpu/drm/nouveau/nv20_graph.c
+++ b/drivers/gpu/drm/nouveau/nv20_graph.c
@@ -454,13 +454,13 @@
 	unsigned long flags;
 
 	spin_lock_irqsave(&dev_priv->context_switch_lock, flags);
-	nv04_graph_fifo_access(dev, false);
+	nv_mask(dev, NV04_PGRAPH_FIFO, 0x00000001, 0x00000000);
 
 	/* Unload the context if it's the currently active one */
 	if (nv10_graph_channel(dev) == chan)
 		nv20_graph_unload_context(dev);
 
-	nv04_graph_fifo_access(dev, true);
+	nv_mask(dev, NV04_PGRAPH_FIFO, 0x00000001, 0x00000001);
 	spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);
 
 	/* Free the context resources */