ath5k: adding LED support for AR5BXB63 cards

With following patch, LED should now work with LiteOn AR5BXB63 mini
pci-e cards.

(Broken patch fixed-up by me...let's hope I did it right! -- JWL)

Signed-off-by: Luca Verdesca <magooz@salug.it>
Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>