ONOS-4417 Remove OtuPort out of core.

Change-Id: Ibc72ee617b238005585f0bcd873b9123e48ee7fc
diff --git a/core/api/src/main/java/org/onosproject/net/device/OtuPortDescription.java b/core/api/src/main/java/org/onosproject/net/device/OtuPortDescription.java
index ac5d855..5495524 100644
--- a/core/api/src/main/java/org/onosproject/net/device/OtuPortDescription.java
+++ b/core/api/src/main/java/org/onosproject/net/device/OtuPortDescription.java
@@ -24,7 +24,10 @@
 
 /**
  * Default implementation of immutable OTU port description.
+ *
+ * @deprecated in Goldeneye (1.6.0)
  */
+@Deprecated
 public class OtuPortDescription extends DefaultPortDescription {
 
     private final OtuSignalType signalType;