WIP: Generate register infrastructure from SystemRDL

This is a draft and I will update this merge request as I'm trying out things. Comments are welcome!

At this point you have to put a list of .rdl files into rdl_deps.txt by hand. This should probably be handled by Tcl functions when the fwk goes through the namespaces.

To compile the .rdl files and generate output products in ./HECTARE:

make rdl