base,cpu,sim: Stop including arch/vtophys.hh when not using vtophys.

base,cpu,sim: Stop including arch/vtophys.hh when not using vtophys.

These #includes are leftovers from when vtophys was used much more
prevalently in the simulator.

Change-Id: Ib2e947bc95f1e21acc9eff8e856f38b31d3fd933
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26225
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>