Clear procedure for adding a new SoC

[coleramos425]

Describe the suggestion Develop and document a clear procedure for adding a new SoC

Justification With the changes in place to encapsulate all SoC unique properties in a class, adding a new SoC will be easier for maintainers. If we document this procedure it will also make things easier for contributors when they want to add an SoC that they're particularly interested in.

Implementation Add relevant comments in source code as well as update documentation so the procedure is clear to external users

Originally posted by @coleramos425 in https://github.com/AMDResearch/omniperf/discussions/153#discussioncomment-6806981

[ppanchad-amd]

Closing since task is completed.