mediatek-mt7622: netgear-wax206 fix wifi leds

the wifi leds of the wax206 were not reacting.
This patch enables the green leds to show activity, as the blue ones are very bright.
Also set the label-mac to the gmac0

Signed-off-by: Florian Maurer <f.maurer@outlook.de>
Link: https://github.com/openwrt/openwrt/pull/17694


Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>