Mechanism to add Port annotation via netcfg

- intended to be used for driver to support ONOS-5895

Change-Id: Iddcf6f1b99273e8f8670b5f64fc9831e5f4ce3cd
diff --git a/core/api/src/main/java/org/onosproject/net/config/Config.java b/core/api/src/main/java/org/onosproject/net/config/Config.java
index 9cea1b9..c7d821e 100644
--- a/core/api/src/main/java/org/onosproject/net/config/Config.java
+++ b/core/api/src/main/java/org/onosproject/net/config/Config.java
@@ -908,4 +908,9 @@
         }
     }
 
+    @Override
+    public String toString() {
+        return String.valueOf(node);
+    }
+
 }