Adding support of Ettus Research SDR devices as target LiteX boards

[ohault]

The community of SDR enthousiasts is growing very fast and is somehow now part of the current FPGA revolution currenly in progress.

In one hand, the well known, Ettus Research is a key SDR hardware provider in at least professional and academic/research circles.
In the other hand, SDR lacks some componentisation aspects and that is where LiteX framework will play a key role.

Reference : https://files.ettus.com/manual/md_fpga.html

[enjoy-digital]

Thanks @ohault, we don't currently have Ettus Research SDRs but if you manage to get/provide some, we could probably put in place initial LiteX-Boards support. Adding full SDR support would probably requires a concrete project to drive this work.