Adding OpenWrt support for MikroTik cAP ac

[slh]

IPQ40xx Switch Config "Strangeness" (swconfig)

Impacting EA8300 and apparently EA6350v3, the IPQ40xx switch in these devices seems to have a mind of its own about VLANs and configuration. From what I've read, this is a "non-standard" switch that may require additional development work to have functional VLANs. It seems as though the two Ethernet phys are internally "wired" to VLANs off switch port 0. These devices appear to be dual-NIC devices, which may be almost certainly are a different wrinkle than dealt with in other threads / patches…