AETHER-3051 Move traffic-class model outside of MBR container

Change-Id: Ib3916d3b417cb8f8d659e823313ae9efbd897044
diff --git a/config-models/aether-2.0.x/files/yang/onf-device-group.yang b/config-models/aether-2.0.x/files/yang/onf-device-group.yang
index b57e8db..2e01e17 100755
--- a/config-models/aether-2.0.x/files/yang/onf-device-group.yang
+++ b/config-models/aether-2.0.x/files/yang/onf-device-group.yang
@@ -103,15 +103,6 @@
           description "Per-device MBR uplink data rate in bps";
         }
 
-        leaf traffic-class {
-          type leafref {
-            path "../../../../traffic-class/tc-id";
-          }
-          mandatory true;
-          description
-            "Link to traffic class";
-        }
-
         leaf downlink {
           type at:bitrate;
           units bps;
@@ -119,6 +110,15 @@
           description "Per-device MBR downlink data rate in bps";
         }
       }
+
+      leaf traffic-class {
+        type leafref {
+          path "../../../traffic-class/tc-id";
+        }
+        mandatory true;
+        description
+          "Link to traffic class";
+      }
     }
   }
 }