supplicant/esp_wifi: move supplicant to idf

Move supplicant to idf and do following refactoring:
1. Make the folder structure consitent with supplicant upstream
2. Remove duplicated header files and minimize the public header files
3. Refactor for WiFi/supplicant interfaces

components/wpa_supplicant/src/utils/ext_password.h

@@ -0,0 +1,33 @@
+/*
+ * External password backend
+ * Copyright (c) 2012, Jouni Malinen <j@w1.fi>
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+
+#ifndef EXT_PASSWORD_H
+#define EXT_PASSWORD_H
+
+struct ext_password_data;
+
+#ifdef CONFIG_EXT_PASSWORD
+
+struct ext_password_data * ext_password_init(const char *backend,
+					     const char *params);
+void ext_password_deinit(struct ext_password_data *data);
+
+struct wpabuf * ext_password_get(struct ext_password_data *data,
+				 const char *name);
+void ext_password_free(struct wpabuf *pw);
+
+#else /* CONFIG_EXT_PASSWORD */
+
+#define ext_password_init(b, p)
+#define ext_password_deinit(d)
+#define ext_password_get(d, n)
+#define ext_password_free(p)
+
+#endif /* CONFIG_EXT_PASSWORD */
+
+#endif /* EXT_PASSWORD_H */