* Ensure we set 20MHz wide channels (hard-coded) for PHY-N.
* Change the core rese tto take a flag saying "gmode" vesus uint32_t
flags. This is important for BCMA support where the "gmode" bit
is different.
* Refactor out the mac-phy clock reset routine (usde by PHY-N).
Tested:
* BCM4321 (PHY-N), BCM4312 (PHY-LP)
TODO:
* Checkpoint test on PHY-G hardware, just to check.
* 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.
