ramips: MiWiFi Nano fixes

Use the the dt-bindings macros and add the reset button.

Set the correct polarity for the LEDs and drop the default state.
Remove all trigger for the LEDs. According to the manual the LEDs are
only used to show the operation state, where blue means normal
operation.

Use the MAC-Addresses stored in EEPROM for the ethernet and the
wireless interface.

Signed-off-by: L. D. Pinney <ldpinney@gmail.com>
[use leds only for boot status indication, add proper commit message]
Signed-off-by: Mathias Kresin <dev@kresin.me>