drm/nouveau: Unregister switcheroo client on exit

Currently nouveau only registers as a vga_switcheroo client, but never
unregisters. This patch adds the necessary unregister calls.
Signed-off-by: Andreas Heider <andreas@meetr.de>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_state.c

@@ -840,6 +840,7 @@ nouveau_card_init(struct drm_device *dev)
 out_display_early:
 	engine->display.late_takedown(dev);
 out:
+	vga_switcheroo_unregister_client(dev->pdev);
 	vga_client_register(dev->pdev, NULL, NULL, NULL);
 	return ret;
 }
@@ -895,6 +896,7 @@ static void nouveau_card_takedown(struct drm_device *dev)
 
 	nouveau_irq_fini(dev);
 
+	vga_switcheroo_unregister_client(dev->pdev);
 	vga_client_register(dev->pdev, NULL, NULL, NULL);
 }