ath9k: Add btcoex profile management support for AR9462

AR9462 chips have the capabilities to provoide bluetooth
profile information. For non-AR9462 btcoex chips, the BT
priority traffic was identified by periodically polling
the respective registers and updated dutycycle, stomptype,
etc. As AR9462 chip offers the BT profile informations,
let us make use of that to update aggregation limit,
dutycycle, stomptype and wieghtages.

Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>