include/linux/mtd: Update copyright notices

Condense these updates down to SPDX tags too while doing this.  This is
a port of a1452a3771c4eb85bd779790b040efdc36f4274e from the Linux
Kernel.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/linux/mtd/doc2000.h b/include/linux/mtd/doc2000.h
index ba29d53..a3cfe6b 100644
--- a/include/linux/mtd/doc2000.h
+++ b/include/linux/mtd/doc2000.h
@@ -1,12 +1,13 @@
 /*
  * Linux driver for Disk-On-Chip devices
  *
- * Copyright (C) 1999 Machine Vision Holdings, Inc.
- * Copyright (C) 2001-2003 David Woodhouse <dwmw2@infradead.org>
- * Copyright (C) 2002-2003 Greg Ungerer <gerg@snapgear.com>
- * Copyright (C) 2002-2003 SnapGear Inc
+ * Copyright © 1999 Machine Vision Holdings, Inc.
+ * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
+ * Copyright © 2002-2003 Greg Ungerer <gerg@snapgear.com>
+ * Copyright © 2002-2003 SnapGear Inc
  *
- * Released under GPL
+ * SPDX-License-Identifier:	GPL-2.0+
+ *
  */
 
 #ifndef __MTD_DOC2000_H__