drm/nouveau/fifo: split user classes out from engine implementations

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/gr/nv35.c b/drivers/gpu/drm/nouveau/nvkm/engine/gr/nv35.c
index d25d330..676234d 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/gr/nv35.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/gr/nv35.c
@@ -2,6 +2,7 @@
 #include "regs.h"
 
 #include <engine/fifo.h>
+#include <engine/fifo/chan.h>
 
 /*******************************************************************************
  * Graphics object classes