arm: Replace most htog and gtoh with htole and letoh.

arm: Replace most htog and gtoh with htole and letoh.

We already know what endianness to use when with ARM. In places where
a ISA was being supplied through an argument, those were left as htog
or gtoh.

Change-Id: Iff01e8b09a061d9a72e657cdd4570836e0da933f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22372
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>