pnp-ids: Use udev's hwdb to query PNP IDs

hwdb has its own database which it compiles to binary, so that:
1) initialisation is practically free
See https://git.gnome.org/browse/gnome-settings-daemon/commit/gnome-settings-daemon/gnome-settings-manager.c?id=d8c158e74caea048dea5a38232bd87c1c7a78a70
2) lookups are also quick, as they use a binary DB
3) we don't have to maintain our own copy of the database
4) allows model lookup rather than simply vendor lookup, when the
   database contains that information

The only problem being that non-Linux OSes will need reimplement this
section of the code. This will be on top of the usual downstream patches
they ship for a number of components.

https://bugzilla.gnome.org/show_bug.cgi?id=590059