support for rlt-1600g-w and rlt-1600x-w in GPON mode

Change-Id: Ib230d3e336043980eb00427384a49cb8bd386bb2
diff --git a/agent/device/rlt-1600x-w/vendor.cc b/agent/device/rlt-1600x-w/vendor.cc
new file mode 100644
index 0000000..86836ff
--- /dev/null
+++ b/agent/device/rlt-1600x-w/vendor.cc
@@ -0,0 +1,21 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "vendor.h"
+
+void vendor_init()
+{
+}