ar9170usb: purge obsolete driver

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/Kconfig

@@ -24,7 +24,6 @@ config ATH_DEBUG
 
 source "drivers/net/wireless/ath/ath5k/Kconfig"
 source "drivers/net/wireless/ath/ath9k/Kconfig"
-source "drivers/net/wireless/ath/ar9170/Kconfig"
 source "drivers/net/wireless/ath/carl9170/Kconfig"
 
 endif