[code-quality] fix clang-tidy mqtt (#7253)

esphome/components/mqtt/mqtt_backend.h

@@ -1,5 +1,6 @@
 #pragma once
-
+#include "esphome/core/defines.h"
+#ifdef USE_MQTT
 #include <string>
 #include <map>
 #include "esphome/components/network/ip_address.h"
@@ -67,3 +68,4 @@ class MQTTBackend {
 
 }  // namespace mqtt
 }  // namespace esphome
+#endif

esphome/components/mqtt/mqtt_backend_esp32.cpp

@@ -1,7 +1,9 @@
+#include "mqtt_backend_esp32.h"
+
+#ifdef USE_MQTT
 #ifdef USE_ESP32
 
 #include <string>
-#include "mqtt_backend_esp32.h"
 #include "esphome/core/log.h"
 #include "esphome/core/helpers.h"
 
@@ -189,3 +191,4 @@ void MQTTBackendESP32::mqtt_event_handler(void *handler_args, esp_event_base_t b
 }  // namespace mqtt
 }  // namespace esphome
 #endif  // USE_ESP32
+#endif

esphome/components/mqtt/mqtt_backend_esp32.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "mqtt_backend.h"
+#ifdef USE_MQTT
 #ifdef USE_ESP32
 
 #include <string>
@@ -7,7 +9,6 @@
 #include <mqtt_client.h>
 #include "esphome/components/network/ip_address.h"
 #include "esphome/core/helpers.h"
-#include "mqtt_backend.h"
 
 namespace esphome {
 namespace mqtt {
@@ -174,3 +175,4 @@ class MQTTBackendESP32 final : public MQTTBackend {
 }  // namespace esphome
 
 #endif
+#endif

esphome/components/mqtt/mqtt_backend_esp8266.h

@@ -1,8 +1,9 @@
 #pragma once
+#include "mqtt_backend.h"
 
+#ifdef USE_MQTT
 #ifdef USE_ESP8266
 
-#include "mqtt_backend.h"
 #include <AsyncMqttClient.h>
 
 namespace esphome {
@@ -70,3 +71,4 @@ class MQTTBackendESP8266 final : public MQTTBackend {
 }  // namespace esphome
 
 #endif  // defined(USE_ESP8266)
+#endif

esphome/components/mqtt/mqtt_backend_libretiny.h

@@ -1,8 +1,9 @@
 #pragma once
+#include "mqtt_backend.h"
 
+#ifdef USE_MQTT
 #ifdef USE_LIBRETINY
 
-#include "mqtt_backend.h"
 #include <AsyncMqttClient.h>
 
 namespace esphome {
@@ -70,3 +71,4 @@ class MQTTBackendLibreTiny final : public MQTTBackend {
 }  // namespace esphome
 
 #endif  // defined(USE_LIBRETINY)
+#endif