This allows to specify and control switch LEDs on devices using mt7530
(typically mediatek and ramips targets).
Normally these LED GPIOs are 0, 3, 6, 9, and 12. wan/lan assignment is
per device. GPIO 9 is normally inverted. so GPIO_ACTIVE_HIGH instead of
GPIO_ACTIVE_LOW.
Tested on Linksys E7350.
Refreshed all patches.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
