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/include/systemace.h b/include/systemace.h
index be43d46..73affc4 100644
--- a/include/systemace.h
+++ b/include/systemace.h
@@ -4,20 +4,7 @@
  * Copyright (c) 2004 Picture Elements, Inc.
  *    Stephen Williams (steve@picturel.com)
  *
- *    This source code is free software; you can redistribute it
- *    and/or modify it in source code form 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.
- *
- *    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+
  */
 #ident "$Id:$"