Adding Copyright notice to files that are missing it

Change-Id: Ic08aad8906dbd4dd062e7adcec7465475cf2bdda
diff --git a/api/src/main/java/org/onosproject/olt/AccessDeviceEvent.java b/api/src/main/java/org/onosproject/olt/AccessDeviceEvent.java
index 7eda5a9..8824cbd 100644
--- a/api/src/main/java/org/onosproject/olt/AccessDeviceEvent.java
+++ b/api/src/main/java/org/onosproject/olt/AccessDeviceEvent.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package org.onosproject.olt;
 
 import org.onlab.packet.VlanId;
diff --git a/api/src/main/java/org/onosproject/olt/AccessDeviceListener.java b/api/src/main/java/org/onosproject/olt/AccessDeviceListener.java
index 9dc4151..14ec982 100644
--- a/api/src/main/java/org/onosproject/olt/AccessDeviceListener.java
+++ b/api/src/main/java/org/onosproject/olt/AccessDeviceListener.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package org.onosproject.olt;
 
 import org.onosproject.event.EventListener;