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/rtl8169.c b/drivers/net/rtl8169.c
index 9864fd7..13fa9c0 100644
--- a/drivers/net/rtl8169.c
+++ b/drivers/net/rtl8169.c
@@ -11,19 +11,7 @@
 *    r8169.c: Etherboot device driver for the RealTek RTL-8169 Gigabit
 *    Written 2003 by Timothy Legge <tlegge@rogers.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.
-*
-*    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * SPDX-License-Identifier:	GPL-2.0+
 *
 *    Portions of this code based on:
 *	r8169.c: A RealTek RTL-8169 Gigabit Ethernet driver