components/bt: Update licenses

examples/bluetooth/esp_ble_mesh/common_components/example_init/ble_mesh_example_init.h

@@ -1,10 +1,8 @@
 /*
-   This example code is in the Public Domain (or CC0 licensed, at your option.)
-
-   Unless required by applicable law or agreed to in writing, this
-   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
-   CONDITIONS OF ANY KIND, either express or implied.
-*/
+ * SPDX-FileCopyrightText: 2021 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
 
 #ifndef _BLE_MESH_EXAMPLE_INIT_H_
 #define _BLE_MESH_EXAMPLE_INIT_H_