Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

[urtwn] migrate urtwn out into sys/dev/urtwn/ .

There's some upcoming work to add new chipset support here and I'd
like to only add 802.11n support to one driver, instead of both
urtwn and rtwn.

There's also missing support for things like 802.11n, some powersave
work, bluetooth integration/coexistence, etc, and also newer parts
(like 8192EU, maybe some 11ac parts, not sure yet.)

So, this is hopefully the first step in a longer set of steps to unify
rtwn/urtwn and extend it with more interesting chipset and functionality
support.

Reviewed by: kevlo

Disable the firwmare licence check for rsu and urtwn.

The licence grant says something exactly the same as the atheros patent
grant, which is "As long as you use this firmware on our chips, everything
is totally okay." Now, I'm pretty sure if that we /have/ to have this,
we're going to have to have it for every other firmware for every other
device in the tree.

So, I'll flip this off in -HEAD for now so people stop asking about
why rsu/urtwn don't work out of the box, and I'll kick off a larger
discussion about this in the new year.

Adding urtwn(4) firmware and related changes.

Reviewed by: rpaulo
Approved by: sbruno (mentor)