USB umass: add quirk to not probe

Some USB WLAN devices have "on-board" storage showing up as umass
and making the root mount wait for a very long time.
The WLAN drivers know how to deal with that an issue an eject
command later when attaching themselves.
Introduce a quirk to not probe these devices as umass and avoid
hangs and confusion altogether.

Reviewed by: hselasky, imp
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D27434