libbsd: Remove BSD-4-Clause from main package

libbsd: Remove BSD-4-Clause from main package

libbsd contains a multitude of licenses. For (commercial) projects the
3rd clause of the BSD-4-Clause license can be problematic. But only a
few man pages use this license. This means that the main package
containing the binary library itself is not under BSD-4-Clause ruling.

Signed-off-by: Mark Jonas <toertel@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>