Original patch by @MPW1412

The TL-WR741ND will identify itself as a TL-WR740N/ND as well. This is fine as
the images are identical anyways.

Recent changes in the routing configuration of OpenWrt broke source address
selection, sometimes leading to the node trying to contact other addresses in
the mesh network from the next-node address.

Revert the problematic commits until this has been solved upstream.

This conflicts with our reset button usage.

With a backported patch from the OpenWrt trunk, it is now easy to generate an
equivalent configuration using CONFIG_ALL_KMODS.

The build will take a bit longer because all kernel module packages are actually
built even when they are not included in the image, but adding new targets
becomes a lot easier.

Also, related documentation updates and fixes.

Also add some patches from OpenWrt trunk and use the CT ath10k firmware.

While it isn't clear why this patch helps, it doesn't seem to have any negative
effects, so let's include it for now...

Otherwise, telnet login is allowed by default when neither a password nor SSH
keys are configured.