[VOL-1385]: code changes to support ONU delete

Change-Id: I8be96e499ccdae29121e81a500a65d0d1a78e5d2
diff --git a/adaptercore/openolt.go b/adaptercore/openolt.go
index 62e34c9..657f249 100644
--- a/adaptercore/openolt.go
+++ b/adaptercore/openolt.go
@@ -376,3 +376,13 @@
 	}
 	return nil
 }
+
+//Child_device_lost deletes the ONU and its references from PONResources
+func (oo *OpenOLT) Child_device_lost(deviceID string, pPortNo uint32, onuID uint32) error {
+	log.Infow("Child-device-lost", log.Fields{"parentId": deviceID})
+	ctx := context.Background()
+	if handler := oo.getDeviceHandler(deviceID); handler != nil {
+		return handler.ChildDeviceLost(ctx, pPortNo, onuID)
+	}
+	return NewErrNotFound("device-handler", log.Fields{"device-id": deviceID}, nil).Log()
+}