drm/nouveau/nvif: split out ctxdma interface definitions

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

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -37,6 +37,7 @@
 #include <core/pci.h>
 #include <core/tegra.h>
 
+#include <nvif/cl0002.h>
 #include <nvif/cla06f.h>
 #include <nvif/if0004.h>