`tx-checksumming` breaks multicast traffic over mesh interfaces.
Add a check in hotplug script to see if interface is mesh interface
and automatically disable `tx-checksumming`.
To keep fork as closely synced with upstream, move NSS packages back
into repository. Not sure why they were moved out from my original fork.
* nss-firmware
* qca-nss-crypto
* qca-nss-cfi
Removed the following:
* mhz (already available in packages repo)
* qrtr (unecessary, and has been broken for years)
Also moved packages out of `qca` and back into root directory.
