iio:adc:lpc32xx use SPDX-License-Identifier

Convert the driver to SPDX license description which allow removing
several lines in the file.
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/lpc32xx_adc.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  *  lpc32xx_adc.c - Support for ADC in LPC32XX
  *
  *  3-channel, 10-bit ADC
  *
  *  Copyright (C) 2011, 2012 Roland Stigge <stigge@antcom.de>
- *
- *  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, write to the Free Software
- *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #include <linux/module.h>