drm/nouveau/kms/nv50: prepare for double-buffered LUTs

We need to double-buffer LUTs to handle their update atomically.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_crtc.h

@@ -60,7 +60,6 @@ struct nouveau_crtc {
 	} cursor;
 
 	struct {
-		struct nouveau_bo *nvbo;
 		int depth;
 	} lut;