libusbgx: bump to v0.2.0
The GitHub tag is really "libusbgx-0.2.0" so we end up with a slightly
strange looking version and archive name, but this is correct given the
tag.
Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>