eeprom: at24: use SPDX identifier instead of GPL boiler-plate

Replace the GPL (or later) header with the SPDX identifier
for GPL-2.0+.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/eeprom/at24.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * at24.c - handle most I2C EEPROMs
  *
  * Copyright (C) 2005-2007 David Brownell
  * Copyright (C) 2008 Wolfram Sang, Pengutronix
- *
- * 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 2 of the License, or
- * (at your option) any later version.
  */
+
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/module.h>