drm/nouveau/fifo/gm206: enable support via gm204 code

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

drivers/gpu/drm/nouveau/nvkm/engine/device/gm100.c

@@ -168,9 +168,9 @@ gm100_identify(struct nvkm_device *device)
 		device->oclass[NVDEV_SUBDEV_VOLT   ] = &nv40_volt_oclass;
 #endif
 		device->oclass[NVDEV_ENGINE_DMAOBJ ] =  gf110_dmaeng_oclass;
-#if 0
-		device->oclass[NVDEV_ENGINE_FIFO   ] =  gk208_fifo_oclass;
+		device->oclass[NVDEV_ENGINE_FIFO   ] =  gm204_fifo_oclass;
 		device->oclass[NVDEV_ENGINE_SW     ] =  gf100_sw_oclass;
+#if 0
 		device->oclass[NVDEV_ENGINE_GR     ] =  gm107_gr_oclass;
 #endif
 		device->oclass[NVDEV_ENGINE_DISP   ] =  gm204_disp_oclass;