treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 81

Based on 1 normalized pattern(s):

  this source code is licensed under the gnu general public license
  version 2 or later see the file copying for more details

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: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520075211.129205147@linutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/xen/events/events_internal.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * Xen Event Channels (internal header)
  *
  * Copyright (C) 2013 Citrix Systems R&D Ltd.
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2 or later.  See the file COPYING for more details.
  */
 #ifndef __EVENTS_INTERNAL_H__
 #define __EVENTS_INTERNAL_H__