mtd: rawnand: denali: use SPDX-License-Identifier and fix license mismatch

Use SPDX-License-Identifier instead of the license boilerplates.

This conversion makes it easier for us to scan the license, then
I notice license mismatch problems.

The license blocks in denali* indicate GPL-2.0 "only", while the
MODULE_LICENSE in denali.c and denali_dt.c is GPL-2.0 "or later"
as explained in include/linux/module.h as follows:

  "GPL"                           [GNU Public License v2 or later]
  "GPL v2"                        [GNU Public License v2]

I fixed the MODULE_LICENSE tags, assuming the license blocks are
the authors' intention.

Also, add missing MODULE_DESCRIPTION/AUTHOR to denali.c

While I am touching the license things, I added my credit to denali.c
because this driver was largely re-written by me in 2017.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/nand/raw/denali.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * NAND Flash Controller Device Driver
  * Copyright © 2009-2010, Intel Corporation and its suppliers.
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
+ * Copyright (c) 2017 Socionext Inc.
+ *   Reworked by Masahiro Yamada <yamada.masahiro@socionext.com>
  */
 
 #include <linux/bitfield.h>
@@ -25,8 +20,6 @@
 
 #include "denali.h"
 
-MODULE_LICENSE("GPL");
-
 #define DENALI_NAND_NAME    "denali-nand"
 
 /* for Indexed Addressing */
@@ -1391,3 +1384,7 @@ void denali_remove(struct denali_nand_info *denali)
 	denali_disable_irq(denali);
 }
 EXPORT_SYMBOL(denali_remove);
+
+MODULE_DESCRIPTION("Driver core for Denali NAND controller");
+MODULE_AUTHOR("Intel Corporation and its suppliers");
+MODULE_LICENSE("GPL v2");

drivers/mtd/nand/raw/denali.h

+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * NAND Flash Controller Device Driver
  * Copyright (c) 2009 - 2010, Intel Corporation and its suppliers.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #ifndef __DENALI_H__

drivers/mtd/nand/raw/denali_dt.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * NAND Flash Controller Device Driver for DT
  *
  * Copyright © 2011, Picochip.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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/clk.h>
@@ -202,6 +194,6 @@ static struct platform_driver denali_dt_driver = {
 };
 module_platform_driver(denali_dt_driver);
 
-MODULE_LICENSE("GPL");
+MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Jamie Iles");
 MODULE_DESCRIPTION("DT driver for Denali NAND controller");

drivers/mtd/nand/raw/denali_pci.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * NAND Flash Controller Device Driver
  * Copyright © 2009-2010, Intel Corporation and its suppliers.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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/errno.h>