No more direct G28 calls

Marlin/src/gcode/calibrate/G28.cpp

@@ -210,7 +210,7 @@
  *  Z   Home to the Z endstop
  *
  */
-void GcodeSuite::G28(const bool always_home_all) {
+void GcodeSuite::G28() {
   if (DEBUGGING(LEVELING)) {
     DEBUG_ECHOLNPGM(">>> G28");
     log_machine_info();
@@ -311,7 +311,6 @@ void GcodeSuite::G28(const bool always_home_all) {
   #if ENABLED(DELTA)
 
     home_delta();
-    UNUSED(always_home_all);
 
     #if ENABLED(IMPROVE_HOMING_RELIABILITY)
       end_slow_homing(slow_homing);
@@ -320,7 +319,7 @@ void GcodeSuite::G28(const bool always_home_all) {
   #else // NOT DELTA
 
     const bool homeX = parser.seen('X'), homeY = parser.seen('Y'), homeZ = parser.seen('Z'),
-               home_all = always_home_all || (homeX == homeY && homeX == homeZ),
+               home_all = homeX == homeY && homeX == homeZ, // All or None
                doX = home_all || homeX, doY = home_all || homeY, doZ = home_all || homeZ;
 
     destination = current_position;

Marlin/src/gcode/gcode.cpp

@@ -277,7 +277,7 @@ void GcodeSuite::process_parsed_command(const bool no_ok/*=false*/) {
         case 27: G27(); break;                                    // G27: Nozzle Park
       #endif
 
-      case 28: G28(false); break;                                 // G28: Home all axes, one at a time
+      case 28: G28(); break;                                      // G28: Home one or more axes
 
       #if HAS_LEVELING
         case 29:                                                  // G29: Bed leveling calibration

Marlin/src/gcode/gcode.h

@@ -434,7 +434,7 @@ private:
     static void G27();
   #endif
 
-  static void G28(const bool always_home_all);
+  static void G28();
 
   #if HAS_LEVELING
     #if ENABLED(G29_RETRY_AND_RECOVER)