thermal/drivers/cpu_cooling: Add Software Package Data Exchange (SPDX)

For license auditing purpose, let's add the SPDX tag.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

drivers/thermal/cpu_cooling.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/drivers/thermal/cpu_cooling.c
  *
@@ -8,21 +9,6 @@
  *  Authors:	Amit Daniel <amit.kachhap@linaro.org>
  *		Viresh Kumar <viresh.kumar@linaro.org>
  *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- *  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; version 2 of the License.
- *
- *  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, write to the Free Software Foundation, Inc.,
- *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
 #include <linux/module.h>
 #include <linux/thermal.h>