[modules] convert rc_settings subsystem to module

conf/firmwares/subsystems/fixedwing/settings_rc.makefile

@@ -1,6 +0,0 @@
-# Hey Emacs, this is a -*- makefile -*-
-
-# change settings via Remote Control, e.g. tune your aircraft
-
-$(TARGET).srcs += rc_settings.c
-$(TARGET).CFLAGS += -DRADIO_CONTROL_SETTINGS

sw/airborne/firmwares/fixedwing/autopilot.c

@@ -74,7 +74,7 @@ static void send_alive(struct transport_tx *trans, struct link_device *dev)
 }
 
 #if defined RADIO_CALIB && defined RADIO_CONTROL_SETTINGS
-#include "rc_settings.h"
+#include "modules/settings/rc_settings.h"
 static void send_rc_settings(struct transport_tx *trans, struct link_device *dev)
 {
   if (!RcSettingsOff()) {

sw/airborne/firmwares/fixedwing/main_ap.c

@@ -74,7 +74,7 @@ PRINT_CONFIG_MSG_VALUE("USE_BARO_BOARD is TRUE, reading onboard baro: ", BARO_BO
 #include "generated/modules.h"
 #include "generated/settings.h"
 #if defined RADIO_CONTROL || defined RADIO_CONTROL_AUTO1
-#include "rc_settings.h"
+#include "modules/settings/rc_settings.h"
 #endif
 #include "subsystems/abi.h"
 

sw/airborne/modules/settings/rc_settings.c

@@ -24,7 +24,7 @@
 
 #include <inttypes.h>
 #include "generated/radio.h"
-#include "rc_settings.h"
+#include "modules/settings/rc_settings.h"
 #include "autopilot.h"
 #include "firmwares/fixedwing/nav.h"
 #include "subsystems/sensors/infrared.h"

sw/airborne/modules/settings/rc_settings.h

@@ -22,7 +22,7 @@
 
 
 /**
- * @file rc_settings.h
+ * @file modules/settings/rc_settings.h
  * Variable setting though the radio control
  *
  * The 'rc_control' section of a XML flight plan allows the user to change the