Add API support for LLDP config/interface set

Add API methods to configure LLDP and set interface to enable/disable.
Also add port description TLV for LLDP.

Change-Id: Ib959d488c2ab8a0069f143558871f41fcc43a5d3
Signed-off-by: Steve Shin <jonshin@cisco.com>
diff --git a/src/vnet/lldp/lldp.h b/src/vnet/lldp/lldp.h
new file mode 100644
index 0000000..473c202
--- /dev/null
+++ b/src/vnet/lldp/lldp.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * 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.
+ */
+/**
+ * @file
+ * @brief LLDP external definition
+ */
+#ifndef __included_lldp_h__
+#define __included_lldp_h__
+
+typedef enum lldp_cfg_err
+{
+  lldp_ok,
+  lldp_not_supported,
+  lldp_invalid_arg,
+} lldp_cfg_err_t;
+
+lldp_cfg_err_t lldp_cfg_intf_set (u32 hw_if_index, u8 ** port_desc, int enable);
+lldp_cfg_err_t lldp_cfg_set (u8 ** host, int hold_time, int tx_interval);
+
+#endif /* __included_lldp_h__ */