[iwn] 6235 support, initial patch

[Adrian Chadd]

Hi,

Here's some fixes from mav, shoehorned into the current driver framework.

Mav - where'd you get your changes from?

http://people.freebsd.org/~adrian/iwn/20131207-iwn-6235-1.diff

This enables the 6235.

It now doesn't firmware panic upon startup. I've passed _no_ traffic
through it though - I don't have pigtails for the connectors on my
NIC. Sorry :(

I've added in mav's changes but I've done it by adding a new 6235
config / limits section rather than hacking up the existing 6000g2b
section. I don't know what effect it'll have on the existing NICs. So
I didn't want to change that behaviour.

This is against the latest -HEAD.

Thanks!



-adrian