openocd: src/target: replace the GPL-2.0-or-later license tag

Replace the FSF boilerplate with the SPDX tag.

The SPDX tag on files *.c is incorrect, as it should use the C99
single line comment using '//'. But current checkpatch doesn't
allow C99 comments, so keep using standard C comments, by now.

Change-Id: I255ad17235ff1e01bf0aa4deed4d944e1d693ddb
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7071
Tested-by: jenkins

src/target/x86_32_common.h

@@ -1,3 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
 /*
  * Copyright(c) 2013-2016 Intel Corporation.
  *
@@ -7,19 +9,6 @@
  * Julien Carreno (julien.carreno@intel.com)
  * Jeffrey Maxwell (jeffrey.r.maxwell@intel.com)
  *
- * 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.
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
  * Contact Information:
  * Intel Corporation
  */