Move Stepper::synchronize to Planner (#10713)

Co-Authored-By: ejtagle <ejtagle@hotmail.com>

Marlin/src/gcode/control/M605.cpp

@@ -43,7 +43,7 @@
    *    Note: the X axis should be homed after changing dual x-carriage mode.
    */
   void GcodeSuite::M605() {
-    stepper.synchronize();
+    planner.synchronize();
     if (parser.seen('S')) dual_x_carriage_mode = (DualXMode)parser.value_byte();
     switch (dual_x_carriage_mode) {
       case DXC_FULL_CONTROL_MODE:
@@ -75,7 +75,7 @@
 #elif ENABLED(DUAL_NOZZLE_DUPLICATION_MODE)
 
   void GcodeSuite::M605() {
-    stepper.synchronize();
+    planner.synchronize();
     extruder_duplication_enabled = parser.intval('S') == (int)DXC_DUPLICATION_MODE;
     SERIAL_ECHO_START();
     SERIAL_ECHOLNPAIR(MSG_DUPLICATION_MODE, extruder_duplication_enabled ? MSG_ON : MSG_OFF);