Add license headers, update namespaces

esp_modem/include/esp_modem_config.h

@@ -1,9 +1,19 @@
+// Copyright 2021 Espressif Systems (Shanghai) PTE LTD
 //
-// Created by david on 2/24/21.
-//
+// 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
 
-#ifndef SIMPLE_CXX_CLIENT_ESP_MODEM_CONFIG_H
-#define SIMPLE_CXX_CLIENT_ESP_MODEM_CONFIG_H
+//     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 _ESP_MODEM_CONFIG_H_
+#define _ESP_MODEM_CONFIG_H_
 #include "driver/uart.h"
 #include "esp_modem_dce_config.h"
 
@@ -64,4 +74,4 @@ struct esp_modem_dte_config {
 
 typedef struct esp_modem_dte_config esp_modem_dte_config_t;
 
-#endif //SIMPLE_CXX_CLIENT_ESP_MODEM_CONFIG_H
+#endif // _ESP_MODEM_CONFIG_H_