drm/nouveau: add support for gm20x fifo channels

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

drivers/gpu/drm/nouveau/nouveau_chan.c

@@ -184,7 +184,8 @@ static int
 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,

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -181,6 +181,7 @@ nouveau_accel_init(struct nouveau_drm *drm)
 			break;
 		case FERMI_CHANNEL_GPFIFO:
 		case KEPLER_CHANNEL_GPFIFO_A:
+		case MAXWELL_CHANNEL_GPFIFO_A:
 			ret = nvc0_fence_create(drm);
 			break;
 		default: