drm/nouveau/mxm: handle DCB 4.1 modification

Allows MXM DCB modification to be handled on GM20x and newer boards.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvkm/subdev/mxm/nv50.c

@@ -190,7 +190,7 @@ mxm_dcb_sanitise(struct nvkm_mxm *mxm)
 	struct nvkm_bios *bios = subdev->device->bios;
 	u8  ver, hdr, cnt, len;
 	u16 dcb = dcb_table(bios, &ver, &hdr, &cnt, &len);
-	if (dcb == 0x0000 || ver != 0x40) {
+	if (dcb == 0x0000 || (ver != 0x40 && ver != 0x41)) {
 		nvkm_debug(subdev, "unsupported DCB version\n");
 		return;
 	}