[ONOS] PCEP provider changes, added node listeners to topology provider

Change-Id: I98bc6445ee78a8f0bf53f897f0a25f678ec7fc99
diff --git a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClientController.java b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClientController.java
index befc3f0..fff6759 100644
--- a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClientController.java
+++ b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClientController.java
@@ -57,7 +57,7 @@
     void removeListener(PcepClientListener listener);
 
     /**
-     * Register a listener for OF msg events.
+     * Register a listener for PCEP msg events.
      *
      * @param listener the listener to notify
      */
@@ -71,6 +71,20 @@
     void removeEventListener(PcepEventListener listener);
 
     /**
+     * Register a listener for PCEP msg events[carrying node descriptor details].
+     *
+     * @param listener the listener to notify
+     */
+    void addNodeListener(PcepNodeListener listener);
+
+    /**
+     * Unregister a listener.
+     *
+     * @param listener the listener to be unregistered
+     */
+    void removeNodeListener(PcepNodeListener listener);
+
+    /**
      * Send a message to a particular pcc client.
      *
      * @param pccId the id of the client to send message.