VOL-2463 : Enable and disable pon/NNI port Core changes

Change-Id: I7671daf47bad2e2a1ba183d458941e033d529ced
diff --git a/common/core/northbound/grpc/default_api_handler.go b/common/core/northbound/grpc/default_api_handler.go
index 38f98fe..f74a1f6 100644
--- a/common/core/northbound/grpc/default_api_handler.go
+++ b/common/core/northbound/grpc/default_api_handler.go
@@ -385,3 +385,12 @@
 	log.Debugw("ListLogicalDeviceMeters-unimplemented", log.Fields{"id": id})
 	return nil, nil
 }
+
+func (handler *DefaultAPIHandler) EnablePort(ctx context.Context, port *voltha.Port) (*empty.Empty, error) {
+	log.Debugw("EnablePort-unimplemented", log.Fields{"id": port.DeviceId})
+	return nil, nil
+}
+func (handler *DefaultAPIHandler) DisablePort(ctx context.Context, port *voltha.Port) (*empty.Empty, error) {
+	log.Debugw("DisablePort-unimplemented", log.Fields{"id": port.DeviceId})
+	return nil, nil
+}