ath79: make all eth ports LAN for Engenius APs

ath79: make all eth ports LAN for Engenius APs

for:
 - ENH202 v1
 - ENS202EXT v1
 - EnstationAC v1
 - EWS511AP

For EWS511AP, have default behavior as static ip
to match the behavior of all other APs in ath79

These boards are sold as
Client Bridge or Point to Point or Access Point
so there is probably no benefit to have WAN by default
for one of the ports, to prevent user confusion.

Signed-off-by: Michael Pratt <mcpratt@pm.me>