ONOS-4417 Remove OtuPort out of core.

Change-Id: Ibc72ee617b238005585f0bcd873b9123e48ee7fc
diff --git a/core/store/dist/src/main/java/org/onosproject/store/device/impl/GossipDeviceStore.java b/core/store/dist/src/main/java/org/onosproject/store/device/impl/GossipDeviceStore.java
index ea25e8c..3af8945 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/device/impl/GossipDeviceStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/device/impl/GossipDeviceStore.java
@@ -1116,8 +1116,14 @@
                 return new DefaultPort(device, number, isEnabled, description.type(),
                                        description.portSpeed(), annotations);
             case OTU:
-                OtuPortDescription otuDesc = (OtuPortDescription) description;
-                return new OtuPort(device, number, isEnabled, otuDesc.signalType(), annotations);
+                if (description instanceof OtuPortDescription) {
+                    // remove if-block once deprecation is complete
+                    OtuPortDescription otuDesc = (OtuPortDescription) description;
+                    return new OtuPort(device, number, isEnabled, otuDesc.signalType(), annotations);
+                }
+                // same as default
+                return new DefaultPort(device, number, isEnabled, description.type(),
+                                       description.portSpeed(), annotations);
             default:
                 return new DefaultPort(device, number, isEnabled, description.type(),
                         description.portSpeed(), annotations);