arch-arm: fix routeToHyp for AArch64 in faults

arch-arm: fix routeToHyp for AArch64 in faults

This patch fixes several bugs in Fault classes "routeToHyp" member
function by which mode checking was not taking into account AArch64
execution state. For the particular case of SVC calls from NS EL0, this
prevented a correct routing to EL2 when HCR_EL2.TGE was set.

Change-Id: I5815fe6dcf4501f52bf92f61687ef6d6ef950e52
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22725
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>