ath9k: Fix regulatory compliance

Adjusting the CCA registers for maximum permissible
noise floor in ETSI/Japan domains has to be done for
all AR9003 family chips.

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