arch-arm: Clean Fault generation when processing Long Descriptor

A new shared method has been introduced: generateLongDescFault

Change-Id: I7eb6fa1347a6c2cf9cb11fd9f2137d983c4f7a40
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19608
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed