treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 371

Based on 1 normalized pattern(s):

  this file is distributed under the gnu general public license gpl
  version 2 june 1991 see the copying file distributed with this
  software for more info

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 1 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081036.343650482@linutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sound/isa/wavefront/wavefront_midi.c

+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) by Paul Barton-Davis 1998-1999
- *
- * This file is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
- * Version 2 (June 1991). See the "COPYING" file distributed with this
- * software for more info.  
  */
 
 /* The low level driver for the WaveFront ICS2115 MIDI interface(s)