rt2400,rt2500: init led_qual for LED_MODE_DEFAULT

Add a check for LED_MODE_DEFAULT so that we use the link LED for rt2400
and rt2500 devices.

Signed-off-by: Andrew Price <andy@andrewprice.me.uk>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>