Move M605 to cpp

Marlin/src/Marlin.cpp

   SYNC_PLAN_POSITION_KINEMATIC();
 }
 
-#if ENABLED(DUAL_X_CARRIAGE) || ENABLED(DUAL_NOZZLE_DUPLICATION_MODE)
-  #include "gcode/control/M605.h"
-#endif
-
 #if ENABLED(LIN_ADVANCE)
   #include "gcode/feature/advance/M900.h"
 #endif

Marlin/src/gcode/control/M605.h → Marlin/src/gcode/control/M605.cpp

  *
  */
 
+#include "../../inc/MarlinConfig.h"
+
+#if ENABLED(DUAL_X_CARRIAGE) || ENABLED(DUAL_NOZZLE_DUPLICATION_MODE)
+
+#include "../gcode.h"
+#include "../../module/motion.h"
+#include "../../module/stepper.h"
+
 #if ENABLED(DUAL_X_CARRIAGE)
 
   /**
    *
    *    Note: the X axis should be homed after changing dual x-carriage mode.
    */
-  void gcode_M605() {
+  void GcodeSuite::M605() {
     stepper.synchronize();
     if (parser.seen('S')) dual_x_carriage_mode = (DualXMode)parser.value_byte();
     switch (dual_x_carriage_mode) {
 
 #elif ENABLED(DUAL_NOZZLE_DUPLICATION_MODE)
 
-  void gcode_M605() {
+  void GcodeSuite::M605() {
     stepper.synchronize();
     extruder_duplication_enabled = parser.intval('S') == (int)DXC_DUPLICATION_MODE;
     SERIAL_ECHO_START();
   }
 
 #endif // DUAL_NOZZLE_DUPLICATION_MODE
+
+#endif // DUAL_X_CARRIAGE || DUAL_NOZZLE_DUPLICATION_MODE

Marlin/src/gcode/gcode.cpp

 extern void gcode_M350();
 extern void gcode_M351();
 extern void gcode_M355();
-extern void gcode_M605();
 extern void gcode_M900();
 extern void gcode_M906();
 extern void gcode_M911();
       #endif // ADVANCED_PAUSE_FEATURE
 
       #if ENABLED(DUAL_X_CARRIAGE) || ENABLED(DUAL_NOZZLE_DUPLICATION_MODE)
-        case 605: // M605: Set Dual X Carriage movement mode
-          gcode_M605();
-          break;
-      #endif // DUAL_X_CARRIAGE
+        case 605: M605(); break;  // M605: Set Dual X Carriage movement mode
+      #endif
 
       #if ENABLED(MK2_MULTIPLEXER)
         case 702: M702(); break;  // M702: Unload all extruders