Aether-3088 change license to Apache-2.0

Change-Id: I42d7535e82065a8031119bee17594d3fb358a1e5
diff --git a/config-models/aether-2.1.x/files/yang/service-group.yang b/config-models/aether-2.1.x/files/yang/service-group.yang
index 8b4add1..55f0f6b 100755
--- a/config-models/aether-2.1.x/files/yang/service-group.yang
+++ b/config-models/aether-2.1.x/files/yang/service-group.yang
@@ -1,6 +1,6 @@
 // SPDX-FileCopyrightText: 2021 Open Networking Foundation
 //
-// SPDX-License-Identifier: LicenseRef-ONF-Member-Only-1.0
+// SPDX-License-Identifier: Apache-2.0
 
 module service-group {
   namespace "http://opennetworking.org/aether/service-group";