boards/*: fix typo Feie => Freie

boards/common/nrf52xxxdk/include/board_common.h

 /*
- * Copyright (C) 2017 Feie Universität Berlin
+ * Copyright (C) 2017 Freie Universität Berlin
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level

boards/nrf52840dk/include/board.h

 /*
- * Copyright (C) 2017 Feie Universität Berlin
+ * Copyright (C) 2017 Freie Universität Berlin
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level

boards/nrf52dk/include/board.h

 /*
- * Copyright (C) 2016-2017 Feie Universität Berlin
+ * Copyright (C) 2016-2017 Freie Universität Berlin
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level

boards/ruuvitag/include/board.h

 /*
- * Copyright (C) 2018 Feie Universität Berlin
+ * Copyright (C) 2018 Freie Universität Berlin
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level

boards/thingy52/include/board.h

 /*
- * Copyright (C) 2017 Feie Universität Berlin
+ * Copyright (C) 2017 Freie Universität Berlin
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level