drm/nouveau/fifo: program NV_PFIFO_FB_TIMEOUT on init

NVGPU and RM both program this value.

Fixes a bunch of random hangs running parallel piglit.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.c

@@ -645,6 +645,7 @@ gf100_fifo_init_pbdmas(struct nvkm_fifo *fifo, u32 mask)
 		nvkm_wr32(device, 0x00221c, ~(1 << 1)); /* PCE1 */
 	}
 
+	nvkm_mask(device, 0x002a04, 0xbfffffff, 0xbfffffff);
 }
 
 static void

drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c

@@ -960,6 +960,7 @@ gk104_fifo_init_pbdmas(struct nvkm_fifo *fifo, u32 mask)
 	struct nvkm_device *device = fifo->engine.subdev.device;
 
 	nvkm_wr32(device, 0x000204, mask);
+	nvkm_mask(device, 0x002a04, 0xbfffffff, 0xbfffffff);
 }
 
 void