ASoC: mpc8610_hpcd: Switch to SPDX identifier

Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: Andra Danciu <andradanciu1997@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/fsl/mpc8610_hpcd.c

-/**
- * Freescale MPC8610HPCD ALSA SoC Machine driver
- *
- * Author: Timur Tabi <timur@freescale.com>
- *
- * Copyright 2007-2010 Freescale Semiconductor, Inc.
- *
- * This file is licensed under the terms of the GNU General Public License
- * version 2.  This program is licensed "as is" without any warranty of any
- * kind, whether express or implied.
- */
+// SPDX-License-Identifier: GPL-2.0
+//
+// Freescale MPC8610HPCD ALSA SoC Machine driver
+//
+// Author: Timur Tabi <timur@freescale.com>
+//
+// Copyright 2007-2010 Freescale Semiconductor, Inc.
 
 #include <linux/module.h>
 #include <linux/interrupt.h>