Add DiscreteResourceCodec for PortNumber

Change-Id: Iedda1a0ba46b3d044f127334a8abdb419dabcd9f
(cherry picked from commit cbd103dfc8057432bb5bef63cd9a3adafe9c06ad)
diff --git a/core/store/dist/src/main/java/org/onosproject/store/resource/impl/Codecs.java b/core/store/dist/src/main/java/org/onosproject/store/resource/impl/Codecs.java
index 41769e2..c16d944 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/resource/impl/Codecs.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/resource/impl/Codecs.java
@@ -17,6 +17,7 @@
 
 import org.onlab.packet.MplsLabel;
 import org.onlab.packet.VlanId;
+import org.onosproject.net.PortNumber;
 import org.onosproject.net.resource.DiscreteResource;
 import org.onosproject.net.resource.DiscreteResourceCodec;
 
@@ -46,6 +47,7 @@
     }
 
     private void init() {
+        codecs.put(PortNumber.class, new PortNumberCodec());
         codecs.put(VlanId.class, new VlanIdCodec());
         codecs.put(MplsLabel.class, new MplsLabelCodec());
     }