Add copyright to abi_check script
#!/usr/bin/env python3
-
+#
+# This file is part of mbed TLS (https://tls.mbed.org)
+#
+# Copyright (c) 2018, Arm Limited, All Rights Reserved
+#
+# Purpose
+#
# This script is a small wrapper around the abi-compliance-checker and
# abi-dumper tools, applying them to compare the ABI and API of the library
# files from two different Git revisions within an Mbed TLS repository.
