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/drivers/net/lan91c96.c b/drivers/net/lan91c96.c
index 11d350e..2bf0068 100644
--- a/drivers/net/lan91c96.c
+++ b/drivers/net/lan91c96.c
@@ -11,25 +11,12 @@
  *       Developed by Simple Network Magic Corporation (SNMC)
  * Copyright (C) 1996 by Erik Stahlman (ES)
  *
- * 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.
- *
- * 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+
  *
  * Information contained in this file was obtained from the LAN91C96
  * manual from SMC.  To get a copy, if you really want one, you can find
  * information under www.smsc.com.
  *
- *
  * "Features" of the SMC chip:
  *   6144 byte packet memory. ( for the 91C96 )
  *   EEPROM for configuration