[bhnd] Standardize bhnd device tables and quirk matching.

This add a bhnd device table mechanism that standardizes matching of
devices on the bhnd(4) bus, discovery of device quirk flags, and should
be pluggable into the new PNPINFO machinery.

Submitted by: Landon Fuller <landonf@landonf.org>
Differential Revision: https://reviews.freebsd.org/D5759