ath - incremental update ar9300 from FreeBSD

* Update to fbsd 61ad4c7509a280c218a389f91026136cec60708e
  (Aug 11 2014).

* Minor adjustments to the ar9300 hal, plus sysctl support for
  forced cold reset.
ath - incremental update ath from FreeBSD

* Update to fbsd 61ad4c7509a280c218a389f91026136cec60708e
  (Aug 11 2014).