Add GPL-2.0+ SPDX-License-Identifier to source files

Signed-off-by: Wolfgang Denk <wd@denx.de>
[trini: Fixup common/cmd_io.c]
Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/board/LaCie/common/cpld-gpio-bus.c b/board/LaCie/common/cpld-gpio-bus.c
index fb9bf8d..9b24dc53 100644
--- a/board/LaCie/common/cpld-gpio-bus.c
+++ b/board/LaCie/common/cpld-gpio-bus.c
@@ -9,10 +9,7 @@
  *
  * Copyright (C) 2013 Simon Guinot <simon.guinot@sequanux.org>
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
+ * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <asm/arch/gpio.h>