The unpriv load/store instruction from M-mode can cause page/access
fault to M-mode if S-mode page table did not have mappings OR it did
not have PMP access permission.
To tackle this, we redirect trap back to S-mode if unpriv load/store
instruction traps in M-mode.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>