This is a big commit with a whole lot of little changes, all in
preparation for PHY-N and rev 5xx firmware.
* add in a write method that does an explicit flush
* change the txpwr recalc type to return an enum, versus just an int.
* add in PHY-N RX frame format bits, for decoding RX RSSI and such
* add in the header space calculation for rev 5xx firmware.
* add in a whole bunch of new types that the newer and 5g phy code
needs. Notably, broadcom has a split 5GHz band concept -
5G-Low, 5G(-Mid) and 5G-High. I kept encountering this at my
day job and wondered whether it was just some marketing thing.
Nope, turns out it isn't; it's an actual PHY thing.
* Add a "am I a siba bus device" method, that returns true.
The aim is to convert all the siba/bhnd specific bits in if_bwn
over to be wrapped in this check, so when landon does a BHND
drive through he knows which bits need updating.
Now, this the /complete/ set of changes for rev 5xx firmware.
Notably, the TX descriptor handling isn't at all done yet and the
format has changed. So don' try blindly flipping this on just yet!
* Break out the 'g' phy code;
* Break out the debugging bits into a separate source file, since
some debugging prints are done in the phy code;
* Make some more chip methods in if_bwn.c public.
This brings the size of if_bwn.c down to 6,805 lines which is now
approaching managable.
