ath9k: Fix LED gpio for AR93xx chipsets.

The LED gpio is incorrectly programmed for AR9300 and so the led
is not working propelry. AR93xx uses gpio 10 for LED and not the
default.

Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>