Remove PortEvent.SwitchPort

- JSON format of util.SwitchPort has changed to match PortEvent.SwitchPort.
  (not sure if it was currently used in public API)
- Note: SwitchPort#toString() format is different. Log messages, etc. may have changed.
   PortEvent.SwitchPort : "(dpid@number)" both decimal
   util.SwitchPort : "00:00:...:01/number" dpid as HexString, number as decimal

- Part of ONOS-1564

Change-Id: I19ea06de7a701f0f7aaae0a7ed6f0726c0133a91
diff --git a/src/main/java/net/onrc/onos/core/topology/TopologyManager.java b/src/main/java/net/onrc/onos/core/topology/TopologyManager.java
index b800d84..190500f 100644
--- a/src/main/java/net/onrc/onos/core/topology/TopologyManager.java
+++ b/src/main/java/net/onrc/onos/core/topology/TopologyManager.java
@@ -24,9 +24,10 @@
 import net.onrc.onos.core.datastore.topology.KVPort;
 import net.onrc.onos.core.datastore.topology.KVSwitch;
 import net.onrc.onos.core.registry.IControllerRegistryService;
-import net.onrc.onos.core.topology.PortEvent.SwitchPort;
 import net.onrc.onos.core.util.Dpid;
 import net.onrc.onos.core.util.EventEntry;
+import net.onrc.onos.core.util.SwitchPort;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;