Should be able to handle all previous GRU variants and more.

Don't attempt to run the neural PLC on the side channel since
we only have one state.

Also, don't code DRED that's redundant with the main packet

Should make synthesis easier in the future

We're back to processing 10 ms at a time and have no need for 40-ms
"superframes".

Add arch to the LPCNet states, but right now it's always set to zero

Repo was filtered to move everything to the dnn/ directory