When comparing to the port assignment in board.d/02_network, a few
devices seem to use the wrong setup of mediatek,portmap.
The corrects the values for mt76x8 subtarget based on the location
of the wan port.
A previous cleanup of obviously wrong values has already been done in
7a387bf9a0d7 ("ramips: mt76x8: fix bogus mediatek,portmap")
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
04b99d9539