mtd: chips: Use SPDX license headers

Some of the files in mtd/chips do not have a SPDX license
header, presumably because the text string "GPL'd" didn't
parse with Thomas rulesets for magic license tagging.

Fix this, the code is initially from RedHat which clearly
targeted the Linux kernel and intended it to be GPLv2.

In any case the original author appears to be David
Woodhouse who can then confirm this.

Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230603185200.3571174-1-linus.walleij@linaro.org

drivers/mtd/chips/cfi_cmdset_0001.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Common Flash Interface support:
  *   Intel Extended Vendor Command Set (ID 0x0001)
  *
- * (C) 2000 Red Hat. GPL'd
+ * (C) 2000 Red Hat.
  *
  *
  * 10/10/2000	Nicolas Pitre <nico@fluxnic.net>

drivers/mtd/chips/cfi_cmdset_0002.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Common Flash Interface support:
  *   AMD & Fujitsu Standard Vendor Command Set (ID 0x0002)
@@ -16,8 +17,6 @@
  * 25/09/2008 Christopher Moore: TopBottom fixup for many Macronix with CFI V1.0
  *
  * Occasionally maintained by Thayne Harbaugh tharbaugh at lnxi dot com
- *
- * This code is GPL
  */
 
 #include <linux/module.h>

drivers/mtd/chips/cfi_cmdset_0020.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Common Flash Interface support:
  *   ST Advanced Architecture Command Set (ID 0x0020)
  *
- * (C) 2000 Red Hat. GPL'd
+ * (C) 2000 Red Hat.
  *
  * 10/10/2000	Nicolas Pitre <nico@fluxnic.net>
  * 	- completely revamped method functions so they are aware and

drivers/mtd/chips/cfi_probe.c

+// SPDX-License-Identifier: GPL-2.0
 /*
    Common Flash Interface probe code.
-   (C) 2000 Red Hat. GPL'd.
+   (C) 2000 Red Hat.
 */
 
 #include <linux/module.h>

drivers/mtd/chips/cfi_util.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Common Flash Interface support:
  *   Generic utility functions not dependent on command set
  *
  * Copyright (C) 2002 Red Hat
  * Copyright (C) 2003 STMicroelectronics Limited
- *
- * This code is covered by the GPL.
  */
 
 #include <linux/module.h>

drivers/mtd/chips/gen_probe.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Routines common to all CFI-type probes.
  * (C) 2001-2003 Red Hat, Inc.
- * GPL'd
  */
 
 #include <linux/kernel.h>

drivers/mtd/chips/jedec_probe.c

+// SPDX-License-Identifier: GPL-2.0
 /*
    Common Flash Interface probe code.
-   (C) 2000 Red Hat. GPL'd.
+   (C) 2000 Red Hat.
    See JEDEC (http://www.jedec.org/) standard JESD21C (section 3.5)
    for the standard this probe goes back to.
 

drivers/mtd/chips/map_ram.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Common code to handle map devices which are simple RAM
- * (C) 2000 Red Hat. GPL'd.
+ * (C) 2000 Red Hat.
  */
 
 #include <linux/module.h>

drivers/mtd/chips/map_rom.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Common code to handle map devices which are simple ROM
- * (C) 2000 Red Hat. GPL'd.
+ * (C) 2000 Red Hat.
  */
 
 #include <linux/module.h>