drm/nouveau/nvif: split out ctxdma interface definitions

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

drivers/gpu/drm/nouveau/nv50_fence.c

@@ -24,6 +24,7 @@
 
 #include <nvif/os.h>
 #include <nvif/class.h>
+#include <nvif/cl0002.h>
 
 #include "nouveau_drm.h"
 #include "nouveau_dma.h"