[chip dv] Deprecate jtag_riscv_agent

[sriyerg]

The jtag_dmi_agent supercedes the jtag_riscv_agent work and provides a more ergonomic way to access the chip over JTAG. As a step towards tech debt reduction, we should replace it with jtag_dmi_agent / sba_access_utils_pkg methods at the chip level soon.

The replacement should be hopefully straightforward, and should take about a day to complete.

@cindychip @tjaychen

[msfschaffner]

@sriyerg do you want to do this deprecation as part of M2, or can this wait until later?

[msfschaffner]

I am moving this into M3 for now - please relabel if that is not accurate.

[tjaychen]

is it fair to say that deprecation of the existing agent (in favor of the new more flexible / abstracted one) is a clean-up activity best left to backlog?

[sriyerg]

I will prefer keeping this as a low priority M3 item. Would it be ok to reevaluate this later when we get close to M3?

[tjaychen]

yes sounds good.