drm/nouveau/gr/gf100-: wait for FE_PWR_MODE_AUTO

This doesn't fix any known issue, but RM started doing it at some point,
so presumably it's needed for something.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgf100.c

@@ -1447,6 +1447,10 @@ gf100_grctx_generate(struct gf100_gr *gr, struct gf100_gr_chan *chan, struct nvk
 
 	/* NV_PGRAPH_FE_PWR_MODE_AUTO. */
 	nvkm_wr32(device, 0x404170, 0x00000010);
+	nvkm_msec(device, 2000,
+		if (!(nvkm_rd32(device, 0x404170) & 0x00000010))
+			break;
+	);
 
 	/* Init SCC RAM. */
 	nvkm_wr32(device, 0x40802c, 0x00000001);