aether-2.0.0 models: Reorganize the YANG tree as submodules

Change-Id: I5c41899b466f7ece528d5e078924589118441104
diff --git a/config-models/aether-2.0.x/files/yang/onf-site.yang b/config-models/aether-2.0.x/files/yang/onf-site.yang
index b5f22c4..2b782ff 100755
--- a/config-models/aether-2.0.x/files/yang/onf-site.yang
+++ b/config-models/aether-2.0.x/files/yang/onf-site.yang
@@ -2,20 +2,28 @@
 //
 // SPDX-License-Identifier: LicenseRef-ONF-Member-Only-1.0
 
-module onf-site {
-  namespace "http://opennetworking.org/aether/site";
-  prefix st;
+submodule onf-site {
+  belongs-to onf-enterprise { prefix ent; }
 
   import ietf-inet-types { prefix inet; }
   import ietf-yang-types{ prefix yg; }
   import onf-aether-types{ prefix at; }
-  import onf-enterprise{ prefix ent; }
+
+  include onf-upf;
+  include onf-vcs;
+  include onf-device-group;
+  include onf-ip-domain;
 
   organization "Open Networking Foundation.";
   contact "Scott Baker";
   description
     "An Aether site is a location where resources are deployed.";
 
+  revision "2022-01-14" {
+    description "Refactored as submodule";
+    reference "RFC 6020";
+  }
+
   revision "2021-09-10" {
     description "An Aether Site.";
     reference "RFC 6087";
@@ -28,15 +36,15 @@
     description "The typedef for site-id";
   }
 
-  container site {
-    description "The top level container";
+  grouping site {
+    description "The site grouping";
 
     list site {
-      key "id";
+      key "site-id";
       description
         "List of site";
 
-      leaf id {
+      leaf site-id {
         type site-id;
         description "ID for this site.";
       }
@@ -117,15 +125,6 @@
             "container for monitoring";
       }
 
-      leaf enterprise {
-        type leafref {
-          path "/ent:enterprise/ent:enterprise/ent:id";
-        }
-        mandatory true;
-        description
-          "Link to enterprise that owns this site";
-      }
-
       container imsi-definition {
         leaf mcc {
           type at:mcc;
@@ -167,6 +166,14 @@
         type at:description;
         description "description of this site";
       }
+
+      uses upf;
+
+      uses vcs;
+
+      uses device-group;
+
+      uses ip-domain;
     }
   }
 }