dev: Added new LupIO-TMR device

This device is a virtual timer that provides both a real-time
counter, as well as a configurable timer with periodic and
one-shot modes.  It uses Ticks to measure time, and is
implemented as a BasicPioDevice.

The following are the specifications regarding the LupIO-TMR:
https://gitlab.com/luplab/lupio/lupio-specs/-/blob/main/lupio-tmr.md

Change-Id: I6fd6f4926494a44d20e1e0289f502535e84d7a69
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/53035
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