ACPI / PMIC: Convert drivers to use SPDX identifier

Reduce size of duplicated comments by switching to use SPDX identifier.

No functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/pmic/intel_pmic_bxtwc.c

@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
- * intel_pmic_bxtwc.c - Intel BXT WhiskeyCove PMIC operation region driver
+ * Intel BXT WhiskeyCove PMIC operation region driver
  *
  * Copyright (C) 2015 Intel Corporation. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 as published by the Free Software Foundation.
- *
- * 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.
  */
 
 #include <linux/init.h>