Support GENEVE tunnel type in OVSDB southbound

Change-Id: I9b93c14d93645ac40525c23bff368e0f81a8189d
diff --git a/core/api/src/main/java/org/onosproject/net/behaviour/TunnelDescription.java b/core/api/src/main/java/org/onosproject/net/behaviour/TunnelDescription.java
index c78ab57..4d9e41b 100644
--- a/core/api/src/main/java/org/onosproject/net/behaviour/TunnelDescription.java
+++ b/core/api/src/main/java/org/onosproject/net/behaviour/TunnelDescription.java
@@ -50,6 +50,10 @@
          */
         GRE,
         /**
+         * Signifies that this is a L3 tunnel.
+         */
+        GENEVE,
+        /**
          * Signifies that this is a L1 OTN tunnel.
          */
         ODUK,