drm/nouveau/fb/ram/gf100-: remove 0x10f200 read

This reg has moved on Pascal, and causes a bus fault.

We never use the value anyway, so just remove the read.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvkm/subdev/fb/ramgf100.c

@@ -638,7 +638,6 @@ gf100_ram_ctor(const struct nvkm_ram_func *func, struct nvkm_fb *fb,
 			return ret;
 	}
 
-	ram->ranks = (nvkm_rd32(device, 0x10f200) & 0x00000004) ? 2 : 1;
 	return 0;
 }