Map license names PSF and PSFv2 to PSF-2.0

According to SDPX.org "Python License 2.0" is the overall Python
license, which is comprised of several licenses. "Python Software
Foundation License 2.0" is part of the complete Python license, but is
also used independently by some projects.

So far the license names PSF and PSFv2 found in LICENSE are mapped to
to Python-2.0. This patch maps PSF and PSFv2 to PSF-2.0 und thus
corrects the impression that Python-2.0 and PSF-2.0 are synonymous.

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