Add Ssqosid extension

[ved-rivos]

1. Adds mstateen0/mstateen0h CSR introduced by Smstateen - only field PRIV114 defined to control access to srmcfg introduced. Other fields need to be added as part of adding related extensions.
2. Adds srmcfg CSR introduced by Ssqosid extension. Access to this CSR at S-mode is governed by PRIV114 bit.
3. Tests: Add tests for Ssqosid extension riscv-non-isa/riscv-arch-test#420
4. Specification: https://github.com/riscv/riscv-ssqosid

[Alasdair]

I left some comments. I think this extension is pretty simple and can be merged once those are addressed.

[github-actions]

Test Results

712 tests  ±0   712 ✅ ±0   0s ⏱️ ±0s
  6 suites ±0     0 💤 ±0 
  1 files   ±0     0 ❌ ±0 

Results for commit 6faa899. ± Comparison against base commit 40ed0c5.

♻️ This comment has been updated with latest results.