Like for the RT-AC54U, this uses a DT trigger for WiFi also at the
RT-AC51U. While at it, rename node and label to wifi2g.
Note that the 5g WiFi LED still isn't supported (see PR #3017 for
further details: https://github.com/openwrt/openwrt/pull/3017 )
Tested-by: Davide Fioravanti <pantanastyle@gmail.com>
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
a1f0fd8cba