Input: 88pm80x_onkey - add SPDX and drop GPL boilerplate

Add a SPDX-License-Identifier to the 88PM80x onkey driver and drop the
GPL boilerplate in accordance with current kernel code guidelines.

Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240121-88pm80x-onkey-spdx-v1-1-b646d4749f5b@skole.hr
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: LegoLivesMatter

drivers/input/misc/88pm80x_onkey.c

@@ -1,22 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Marvell 88PM80x ONKEY driver
  *
  * Copyright (C) 2012 Marvell International Ltd.
  * Haojian Zhuang <haojian.zhuang@marvell.com>
  * Qiao Zhou <zhouqiao@marvell.com>
- *
- * This file is subject to the terms and conditions of the GNU General
- * Public License. See the file "COPYING" in the main directory of this
- * archive for more details.
- *
- * 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/kernel.h>