Add LGPL-2.1+ SPDX-License-Identifier to source files

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/Licenses/README b/Licenses/README
index b879fea..c1d7d11 100644
--- a/Licenses/README
+++ b/Licenses/README
@@ -47,3 +47,4 @@
 =======================================================================================================================================
 GNU General Public License v2.0 only		GPL-2.0		Y		gpl-2.0.txt	http://www.gnu.org/licenses/gpl-2.0.txt
 GNU General Public License v2.0 or later	GPL-2.0+	Y		gpl-2.0.txt	http://www.gnu.org/licenses/gpl-2.0.txt
+GNU Lesser General Public License v2.1 or later	LGPL-2.1+	Y		lgpl-2.1.txt	http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt