IPQ4019: Adding Support For Tp Link Deco M9 Plus

[meshing]

@Hostle @naf @robimarko @troed
Thanks for all the help....

Also this post helped a bit too:

R7500v2 (ath10k 9980) netperf observations, firmware/board-2.bin files, and other wifi issues

A worked example to create your own 99X0 ath10k "firmware-5.bin" and "board-2.bin" files from "stock Netgear" firmware. First a few caveats. At the time this post was written, it seems there is no "redistribution licence" for a "board-2.bin" one might create themselves. As I'm not aware that anything has changed since then and I expect the same is true for a "firmware-5.bin," I will not "redistribute" any such files here or elsewhere. I do not recommend anyone else redistribute any such fil…