ath5k: Support LED's on Acer Extensa 5620z

Add vendor ID for Quanta Microsystems and update the led table with the reported device.

Reported-by: Scott Barnes <nekoreeve@gmail.com>

Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>