wifi: refactor code to match ethernet's init function structure

components/esp32/wifi_init.c

@@ -0,0 +1,23 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// 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.
+
+#include <esp_event.h>
+#include <esp_wifi.h>
+#include "esp_wifi_internal.h"
+
+esp_err_t esp_wifi_init(wifi_init_config_t *config)
+{
+     esp_event_set_default_wifi_handlers();
+     return esp_wifi_init_internal(config);
+}