Add missing license and SPDX id

Author: pea-pod

features/storage/kvstore/include/InitModeFlags.h

@@ -1,3 +1,19 @@
+/*
+ * Copyright (c) 2020 ARM Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ * 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.
+ */
+
 #ifndef MBED_INIT_MODE_FLAGS_H
 #define MBED_INIT_MODE_FLAGS_H