Disallow REPRAPWORLD_KEYPAD moves on Delta/SCARA until homed

Marlin/ultralcd.cpp

@@ -1842,7 +1842,7 @@ menu_edit_type(unsigned long, long5, ftostr5, 0.01);
     lcd_move_y();
   }
   static void reprapworld_keypad_move_home() {
-    enqueue_and_echo_commands_P((PSTR("G28"))); // move all axis home
+    enqueue_and_echo_commands_P(PSTR("G28")); // move all axes home
   }
 #endif // REPRAPWORLD_KEYPAD
 
@@ -2091,13 +2091,22 @@ void lcd_update() {
     #if ENABLED(ULTIPANEL)
 
       #if ENABLED(REPRAPWORLD_KEYPAD)
+
+        #if ENABLED(DELTA) || ENABLED(SCARA)
+          #define _KEYPAD_MOVE_ALLOWED (axis_homed[X_AXIS] && axis_homed[Y_AXIS] && axis_homed[Z_AXIS])
+        #else
+          #define _KEYPAD_MOVE_ALLOWED true
+        #endif
+
+        if (REPRAPWORLD_KEYPAD_MOVE_HOME)       reprapworld_keypad_move_home();
+        if (_KEYPAD_MOVE_ALLOWED) {
           if (REPRAPWORLD_KEYPAD_MOVE_Z_UP)     reprapworld_keypad_move_z_up();
           if (REPRAPWORLD_KEYPAD_MOVE_Z_DOWN)   reprapworld_keypad_move_z_down();
           if (REPRAPWORLD_KEYPAD_MOVE_X_LEFT)   reprapworld_keypad_move_x_left();
           if (REPRAPWORLD_KEYPAD_MOVE_X_RIGHT)  reprapworld_keypad_move_x_right();
           if (REPRAPWORLD_KEYPAD_MOVE_Y_DOWN)   reprapworld_keypad_move_y_down();
           if (REPRAPWORLD_KEYPAD_MOVE_Y_UP)     reprapworld_keypad_move_y_up();
-        if (REPRAPWORLD_KEYPAD_MOVE_HOME)     reprapworld_keypad_move_home();
+        }
       #endif
 
       bool encoderPastThreshold = (abs(encoderDiff) >= ENCODER_PULSES_PER_STEP);