hwdb: also add the source files to git

hwdb: also add the source files to git

Without the original files it's hard to see what changed "upstream", and what
entries were added and removed. Upstream did not keep the entries sorted, and
our processing scripts did not sort the output either, so from just looking at
diffs it's hard to say what changed. So let's keep the original data, at least
for a few update cycles, so get a better handle on the upstream changes.

It's a few hundred kilobytes, so not that big, and text, so it should
compresses well.