drm/nouveau: allow static performance level setting

Guarded by a module parameter for the moment, read the code for the
magic value which enables it.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index bda4d1e..8d36ed6 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -716,6 +716,8 @@
 extern int nouveau_nofbaccel;
 extern int nouveau_noaccel;
 extern int nouveau_override_conntype;
+extern char *nouveau_perflvl;
+extern int nouveau_perflvl_wr;
 
 extern int nouveau_pci_suspend(struct pci_dev *pdev, pm_message_t pm_state);
 extern int nouveau_pci_resume(struct pci_dev *pdev);