Update bitfield syntax

[jordancarlin]

Update remaining uses of old bitfield syntax and replace with the newer syntax (see #373).

The latest version of the sail repo gives the below deprecation warning, which I assume will be included in the next release of sail. This prevents warning messages when that happens.

Warning: Deprecated model/riscv_pmp_regs.sail:71.19-34:
71 |  let match_type = pmpcfg_n[n].A();
   |                   ^-------------^
   | 
Old bitfield syntax, use '<bitfield>[A]' instead

[github-actions]

Test Results

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

Results for commit 3dcc942. ± Comparison against base commit 5168ced.

♻️ This comment has been updated with latest results.

[Timmmm]

Thanks!