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/arch/powerpc/cpu/mpc85xx/p1010_serdes.c b/arch/powerpc/cpu/mpc85xx/p1010_serdes.c
index 1f7dba0..4b965f7 100644
--- a/arch/powerpc/cpu/mpc85xx/p1010_serdes.c
+++ b/arch/powerpc/cpu/mpc85xx/p1010_serdes.c
@@ -2,10 +2,7 @@
  * Copyright 2011 Freescale Semiconductor, Inc.
  * Author: Prabhakar Kushwaha <prabhakar@freescale.com>
  *
- * 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 <config.h>