drm/nouveau: rename nouveau_drm.h to nouveau_drv.h

Fixes out-of-tree build issue where uapi/drm/nouveau_drm.h gets picked
up instead.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_platform.h b/drivers/gpu/drm/nouveau/nouveau_platform.h
index f41056d..a90d727 100644
--- a/drivers/gpu/drm/nouveau/nouveau_platform.h
+++ b/drivers/gpu/drm/nouveau/nouveau_platform.h
@@ -21,7 +21,7 @@
  */
 #ifndef __NOUVEAU_PLATFORM_H__
 #define __NOUVEAU_PLATFORM_H__
-#include "nouveau_drm.h"
+#include "nouveau_drv.h"
 
 extern struct platform_driver nouveau_platform_driver;
 #endif