Merge r226465 (below message) and r226467 (subsequent compile fixes).

Merge r226465 (below message) and r226467 (subsequent compile fixes).

Fix an issue with 11g beacon frames which looks to be a limitation
on the largest multi-write size.

From the submitter:

==
I looked further into the magic 88-byte threshold after which the bug
occurs.  It turns out that figure included the 24-byte tx_desc, and up
to 64 bytes of beacon frame (header+data).

rum_write_multi doesn't seem happy with writing >64 bytes at a time to
the MAC register.  If I break it up into separate calls (e.g. bytes
0-63, then bytes 64-65, written at the appropriate offset) I see the
proper beacon frames being transmitted now.
==

Submitted by:	Steven Chamberlain <steven@pyro.eu.org>

git-svn-id: svn://svn.freebsd.org/base/stable/8@226624 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f