grml-hwinfo: Add inxi output

grml-hwinfo: Add inxi output

* `inxi -F -xx` shows full with extra data level 2 output for inxi
  (except some verbose options)
* `inxi -FJ --admin` shows full with admin extra data (which sets extra
  data level 3) and `-J` which shows USB data for attached Hubs and
  Devices.

Extra Data Level 2 is enough for most use cases, but admin extra data
should show everything possible.

Closes: grml/grml-hwinfo#8