[legal] Relicense files under GPL2_OR_LATER_OR_UBDL

Relicense files for which I am the sole author (as identified by
util/relicense.pl).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
diff --git a/src/config/ioapi.h b/src/config/ioapi.h
index ce19c6d..abe5a50 100644
--- a/src/config/ioapi.h
+++ b/src/config/ioapi.h
@@ -7,7 +7,7 @@
  *
  */
 
-FILE_LICENCE ( GPL2_OR_LATER );
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #include <config/defaults.h>