Atheros ath9k rfkill support

configname: CONFIG_ATH9K_RFKILL

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Wireless LAN
└─>Atheros ath9k rfkill support
In linux kernel since version 3.12 (release Date: 2013-11-03)  
Say Y to have ath9k poll the RF-Kill GPIO every couple of
seconds. Turn off to save power, but enable it if you have
a platform that can toggle the RF-Kill GPIO.