AR9287 based devices have issues with ADC gain calibration
which would cause uplink throughput drops in HT40 mode.
Remove ADC gain from the supported calibration algorithms.
Signed-off-by: NSujith Manoharan <Sujith.Manoharan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>