recipetool/create_buildsys_python: treat BSD as BSD-3-Clause
The PyPI license classifiers include "OSI Approved: BSD", which does not
specify which of the many variations of BSD license it actually means.
The generic "BSD" license in the oe-core set is actually BSD-3-Clause.
>From a random sample of ten PyPI modules that use "BSD", they are all
BSD-3-Clause. As we expect the recipe maintainer to verify the license
anyway, and this matches the previous license text, explicitly set the
license to BSD-3-Clause.
Signed-off-by: Ross Burton <ross.burton@arm.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
