cpu: Additional TrafficGen stats

Additional stats to keep track of read/write latencies and throughput.

Change-Id: I7684cd33cf68fffdef4ca9c3a6db360a0f531c18
Signed-off-by: Tiago Muck <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18418
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed