• Add iwi-firmware, Intel Pro/Wireless Lan 2200 firmware to be used

in conjunction with iwi(4). iwi(4) had already been included in HEAD, but
according to Damien Bergamini, there are no plans to MFC it to RELENG_5.
There is an option (WITH_)MODULE to build and install an iwi(4) module
from a snapshot if you're running RELENG_5.

Note: As of the date of this commit, it seems there are issues with the
iwi(4) snapshot and you might experience some problems.