Don't make the led_control() call for the RT-AC68U LED_5G re-apply led behaviour to the controler, as it causes erratic blinking behaviour - the watchdog periodically calls led_control() to make the 5G LED blink through software.

Now we only write to gpio on a led_control(LED_5G, state) call, and have a separate constant called LED_5G_FORCED which will actually setup the led behaviour register.

Made Stealth Mode use the new constant.