ath9k_hw: change AR9580 initvals to fix a stability issue

The hardware parsing of Control Wrapper Frames needs to be disabled, as
it has been causing spurious decryption error reports. The initvals for
other chips have been updated to disable it, but AR9580 was left out for
some reason.

Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>