mqtt: Moves mqtt_supported_features to public includes.

- To simplify user code to support multiple IDF versions.

Closes https://github.com/espressif/esp-mqtt/issues/184

lib/include/mqtt_supported_features.h

@@ -1,63 +0,0 @@
-// Copyright 2015-2019 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.
-
-#ifndef _MQTT_SUPPORTED_FEATURES_H_
-#define _MQTT_SUPPORTED_FEATURES_H_
-
-#if __has_include("esp_idf_version.h")
-#include "esp_idf_version.h"
-#endif
-
-/**
- * @brief This header defines supported features of IDF which mqtt module
- *        could use depending on specific version of ESP-IDF.
- *        In case "esp_idf_version.h" were not found, all additional
- *        features would be disabled
- */
-
-#ifdef ESP_IDF_VERSION
-
-#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(3, 3, 0)
-// Features supported from 3.3
-#define MQTT_SUPPORTED_FEATURE_EVENT_LOOP
-#define MQTT_SUPPORTED_FEATURE_SKIP_CRT_CMN_NAME_CHECK
-#endif
-
-#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 0, 0)
-// Features supported in 4.0
-#define MQTT_SUPPORTED_FEATURE_WS_SUBPROTOCOL
-#define MQTT_SUPPORTED_FEATURE_TRANSPORT_ERR_REPORTING
-#endif
-
-#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 1, 0)
-// Features supported in 4.1
-#define MQTT_SUPPORTED_FEATURE_PSK_AUTHENTICATION
-#define MQTT_SUPPORTED_FEATURE_DER_CERTIFICATES
-#define MQTT_SUPPORTED_FEATURE_ALPN
-#define MQTT_SUPPORTED_FEATURE_CLIENT_KEY_PASSWORD
-#endif
-
-#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 2, 0)
-// Features supported in 4.2
-#define MQTT_SUPPORTED_FEATURE_SECURE_ELEMENT
-#endif
-
-#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 3, 0)
-// Features supported in 4.3
-#define MQTT_SUPPORTED_FEATURE_DIGITAL_SIGNATURE
-#define MQTT_SUPPORTED_FEATURE_TRANSPORT_SOCK_ERRNO_REPORTING
-#endif
-
-#endif /* ESP_IDF_VERSION */
-#endif // _MQTT_SUPPORTED_FEATURES_H_