treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 44

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of gnu general public license as published by the
  free software foundation either version 2 of the license or at your
  option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170858.279640225@linutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

crypto/cast_common.c

+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Common lookup tables for CAST-128 (cast5) and CAST-256 (cast6)
  *
  * Copyright © 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
  * Copyright © 2003 Kartikey Mahendra Bhatt <kartik_me@hotmail.com>
  * Copyright © 2012 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of 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/module.h>