Fix/Update copyright notices; Add SPDX annotation
Let's fix some erroneous/accidential references to wrong license,
update copyright information where applicable and introduce a
SPDX-License-Identifier to all files.
Change-Id: I39af26c6aaaf5c926966391f6565fc5936be21af
diff --git a/src/coding/gsm0503_coding.c b/src/coding/gsm0503_coding.c
index 639d2df..cacc612 100644
--- a/src/coding/gsm0503_coding.c
+++ b/src/coding/gsm0503_coding.c
@@ -6,6 +6,8 @@
*
* All Rights Reserved
*
+ * SPDX-License-Identifier: GPL-2.0+
+ *
* 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