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/arm/include/asm/bootm.h b/arch/arm/include/asm/bootm.h
index 2c4fa19..436c35a 100644
--- a/arch/arm/include/asm/bootm.h
+++ b/arch/arm/include/asm/bootm.h
@@ -4,20 +4,9 @@
  * Copyright (C) 2011
  * Corscience GmbH & Co. KG - Simon Schwarz <schwarz@corscience.de>
  *
- * 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+
  *
- * This program is distributed in the hope that 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- *
+ * SPDX-License-Identifier:	GPL-2.0+
  */
 #ifndef ARM_BOOTM_H
 #define ARM_BOOTM_H