gpio: crystalcove: Convert 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>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

drivers/gpio/gpio-crystalcove.c

@@ -1,17 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
- * gpio-crystalcove.c - Intel Crystal Cove GPIO Driver
+ * Intel Crystal Cove GPIO Driver
  *
  * Copyright (C) 2012, 2014 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.
- *
  * Author: Yang, Bin <bin.yang@intel.com>
  */