[UniFi AP v2] MTD partition map and DTS support

Just got a UniFi AP v2, and happened to look at the notes on the ToH for this access point. So got myself to fix the partition scheme and the DTS to match the v2 board of the UAP series so I could finally use the thing without having to deploy a UniFi controller.

If you wanna know more and maybe improve on things you can check the DTS repo: