Update German language, (c) (#14804)

Marlin/src/HAL/HAL_DUE/Tone.cpp

@@ -5,6 +5,8 @@
  * Based on Sprinter and grbl.
  * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or