drm/nouveau/kms: add 8.1Gbps DP link rate

This was already done in dcb.c inside nvkm, but the other parser did not
get the update.
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_bios.c

@@ -1478,9 +1478,13 @@ parse_dcb20_entry(struct drm_device *dev, struct dcb_table *dcb,
 		case 1:
 			entry->dpconf.link_bw = 270000;
 			break;
-		default:
+		case 2:
 			entry->dpconf.link_bw = 540000;
 			break;
+		case 3:
+		default:
+			entry->dpconf.link_bw = 810000;
+			break;
 		}
 		switch ((conf & 0x0f000000) >> 24) {
 		case 0xf: