Refactored LLDP link discovery to be shared by multiple providers

Change-Id: Ia2253ff6bb39186e936ddbaff0c416aa5be6e117
diff --git a/providers/netcfglinks/src/test/java/org/onosproject/provider/netcfglinks/NetworkConfigLinksProviderTest.java b/providers/netcfglinks/src/test/java/org/onosproject/provider/netcfglinks/NetworkConfigLinksProviderTest.java
index 70d2245..a16ba15 100644
--- a/providers/netcfglinks/src/test/java/org/onosproject/provider/netcfglinks/NetworkConfigLinksProviderTest.java
+++ b/providers/netcfglinks/src/test/java/org/onosproject/provider/netcfglinks/NetworkConfigLinksProviderTest.java
@@ -104,6 +104,15 @@
         public void addListener(DeviceListener listener) {
             deviceListener = listener;
         }
+
+        @Override
+        public Device getDevice(DeviceId deviceId) {
+            if (deviceId.equals(dev1.id())) {
+                return dev1;
+            } else {
+                return dev2;
+            }
+        }
     }
 
     /**