mem-ruby: Make DMASequencer aware of Atomics

Add handling for issuing atomic packet types, setting the WriteMask and
AtomicOpFunctor in makeRequest. Add an atomicCallback to handle atomic
packet type responses.

Change-Id: I9775fc110bb99a1740089746f0d1b3deb124b9f5
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33716
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
4 files changed