Add SPDX lines to each imported TinyCrypt file
Out of the 6 tinycrypt files included in Mbed TLS, this commit adds SPDX lines
to each for the BSD 3 Clause licence.
diff --git a/include/tinycrypt/ecc_dsa.h b/include/tinycrypt/ecc_dsa.h
index cc5eebc..349f061 100644
--- a/include/tinycrypt/ecc_dsa.h
+++ b/include/tinycrypt/ecc_dsa.h
@@ -4,6 +4,8 @@
* Copyright (c) 2014, Kenneth MacKay
* All rights reserved.
*
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*