arch-riscv: add pma/pmp checks during page table walks

This change adds pma/pmp checks when page table entries
are accessed by hardware page table walker.

Change-Id: I161aad514bb7421e61a8c56af088c73969837704
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46279
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
3 files changed