ath5k: add led pin configuration for compaq c700 laptop

With this patch, a compaq c700 can turn on the wifi led.
The array of compatible devices now includes the hardware
present in this computer, as well as the led pin and
polarity.

Signed-off-by: Marcos Chaparro <nitrousnrg@gmail.com>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>