dev: Added new Lupio-SYS device

This adds the LupIO system controller, in which we provide a
way to halt or reboot the system.  It is implemented as a
BasicPIODevice.

Change-Id: I0031ac65d2aaca3460dcd4c59543a75230b0b52a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/53043
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
4 files changed