arch-arm: Implement ARM8.1-VHE feature

arch-arm: Implement ARM8.1-VHE feature

This commit implemented the VHE feature in ARMv8. This consist in 3
parts
    1. Register decl/init and register redirection from el1 to el2
        miscregs.cc/hh
        miscregs_types.hh
        isa.cc
        utility.cc/hh
    2. Definition of new EL2&0 translation regime.
        tlb.cc/hh
        table_walker.cc
        pagetable.hh
        tlbi_op.hh
        isa.cc ( for tlb invalidation functions)
    3. Self Debug adaptation for VHE
        self_debug.cc
    4. Effects on AMO/IMO/FMO interruptions
        faults.cc
        interrupts.hh

JIRA: https://gem5.atlassian.net/browse/GEM5-682

Change-Id: I478389322c295b1ec560571071626373a8c2af61
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/31177
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>