Fix GENERIC-RESOURCE-API yang validation issues

when validate GENERIC-RESOURCE-API.yang with "pyang" has some issues

Change-Id: Ibdc71e5a369a6815766e42667beacc4a262dc196
Issue-Id: SDNC-99
Signed-off-by: Ramu N <ramu.n@huawei.com>
diff --git a/generic-resource-api/model/src/main/yang/GENERIC-RESOURCE-API.yang b/generic-resource-api/model/src/main/yang/GENERIC-RESOURCE-API.yang
index 233fbaf..f1b8014 100644
--- a/generic-resource-api/model/src/main/yang/GENERIC-RESOURCE-API.yang
+++ b/generic-resource-api/model/src/main/yang/GENERIC-RESOURCE-API.yang
@@ -1229,7 +1229,7 @@
             }

          }

          list vnf-networks {

-            key "";

+            key "network-role";

             uses vnf-network;

             uses sriov-vlan-filter-list;

          }

@@ -1253,7 +1253,7 @@
             }

          }

          list vm-networks {

-            key "";

+            key "network-role";

             uses vm-network;

          }

       }