{drivers,ec/kontron}: Replace GPLv2 long form headers with SPDX header

Change-Id: Ide6cfd6f79bd54f50d9fde37c55f2b0df702478a
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41135
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/ec/kontron/kempld/kempld_i2c.c

@@ -1,18 +1,11 @@
+/* This file is part of the coreboot project. */
+/* SPDX-License-Identifier: GPL-2.0-only */
+
 /*
  * I2C bus driver for Kontron COM modules
  *
  * Based on the similar driver in Linux.
  */
-/*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License 2 as published
- * by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
 
 #include <stdint.h>
 #include <console/console.h>