Add an example configuration for gem5 that runs the DRAMSys simulator with a TrafficGenerator initiator. Change-Id: If90f49fcc05b73905b2f9dc8b7aadfdbd866340a Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/62913 Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu> Maintainer: Bobby Bruce <bbruce@ucdavis.edu> Tested-by: kokoro <noreply+kokoro@google.com>