AP_Arming: untangle header inclusion

libraries/AP_Arming/AP_Arming.cpp

@@ -14,12 +14,14 @@
  */
 
 #include "AP_Arming.h"
+#include <AP_BoardConfig/AP_BoardConfig.h>
+#include <AP_BattMonitor/AP_BattMonitor.h>
 #include <AP_Notify/AP_Notify.h>
-#include <SRV_Channel/SRV_Channel.h>
 #include <GCS_MAVLink/GCS.h>
-#include <AP_BoardConfig/AP_BoardConfig.h>
+#include <GCS_MAVLink/GCS_MAVLink.h>
 #include <AP_Mission/AP_Mission.h>
 #include <AP_Rally/AP_Rally.h>
+#include <SRV_Channel/SRV_Channel.h>
 
 #define AP_ARMING_COMPASS_MAGFIELD_EXPECTED 530
 #define AP_ARMING_COMPASS_MAGFIELD_MIN  185     // 0.35 * 530 milligauss

libraries/AP_Arming/AP_Arming.h

@@ -1,10 +1,8 @@
 #pragma once
 
-#include <AP_AHRS/AP_AHRS.h>
-#include <AP_BattMonitor/AP_BattMonitor.h>
 #include <AP_HAL/AP_HAL.h>
 #include <AP_Param/AP_Param.h>
-#include <GCS_MAVLink/GCS_MAVLink.h>
+#include <AP_AHRS/AP_AHRS.h>
 #include <RC_Channel/RC_Channel.h>
 
 class AP_Arming {