Clean up licensing information
This package has an interesting mix of licenses which are considered problematic in Apertis.
In the end there's no particular issue:
- the overall license is
BSD-3-Clause-Attribution
, notBSD-4-Clause
- some files are
BSD-4-Clause-UC
, which is benign - the actual
BSD-4-Clause
files are not used in practice
Edited by Emanuele Aina