patches for if_iwi and wlan for WEP mode

[Mitsuru IWASAKI]

Hi,

> I'd rather you didn't commit iwi_update_mcast() unless you absolutely
> know that the NIC doesn't need to be notified of multicast group
> membership changes. If so, please commit that as a separate fix.

OK, I'd do so.  I don't need mcast stuff for the time being,
instead I'd check other area such as suspend/resume for the next target.

Today's one at:
http://people.freebsd.org/~iwasaki/iwi/iwi-20120308.diff

# 2 lines fix, after all ;)

Thanks!