Fix broken WAN on Linksys EAX and Asrock G10 by incrementing the WAN
interface MAC address + 1. This caused conflicting entry in the FDB
table and caused the WAN port to malfunction with the DSA conversion.
Fixes: #17157Fixes: #15585Fixes: #16604
Link: https://github.com/openwrt/openwrt/pull/17839
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>