drm/nouveau: add support for gm20x fifo channels

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_chan.c b/drivers/gpu/drm/nouveau/nouveau_chan.c
index e581f63..0589bab 100644
--- a/drivers/gpu/drm/nouveau/nouveau_chan.c
+++ b/drivers/gpu/drm/nouveau/nouveau_chan.c
@@ -184,7 +184,8 @@
 nouveau_channel_ind(struct nouveau_drm *drm, struct nvif_device *device,
 		    u32 handle, u32 engine, struct nouveau_channel **pchan)
 {
-	static const u16 oclasses[] = { KEPLER_CHANNEL_GPFIFO_A,
+	static const u16 oclasses[] = { MAXWELL_CHANNEL_GPFIFO_A,
+					KEPLER_CHANNEL_GPFIFO_A,
 					FERMI_CHANNEL_GPFIFO,
 					G82_CHANNEL_GPFIFO,
 					NV50_CHANNEL_GPFIFO,