tree a4729f4155664cc7c35973a5d9c09da168b04ea9
parent df9480e9457b450bf701b3763b826b98fdeb1bf5
author Alex Van Damme <atv@google.com> 1701811493 -0800
committer Alex Van Damme <atv@google.com> 1701999273 -0800

Add CSRs touched by riscv-tests, and a new `kisa` CSR

- riscv-tests uses a few CSRs that we did not explicitly implement
  (version/architecture CSRs) -- define them in the HDL so we can
  potentially give them meaningful values in the near future.
- Add a custom CSR `kisa`, which is intended to help software detect
  what version of Kelvin they're running on, and what features it
  supports. Initially, the value of the CSR is 0, which indicates that
  Kelvin only supports the features of the initial open-source release.

Change-Id: Ide3362805e72d8970f02c351c491ec0d5fbb67ad