config: Add a DRAM efficiency-sweep script
config: Add a DRAM efficiency-sweep script

This patch adds a configuration that simplifies evaluation of DRAM
controller configurations by automating a sweep of stride size and
bank parallelism. It works in a rather unconventional way, as it needs
to print the traffic generator stimuli based on the memory
organisation. Hence, it starts by configuring the memory, then it
prints a traffic-generator config file, and loads it.

The resulting stats have one period per data point, identified by the
stride size, and the number of banks being used.
(transplanted from 45d16673b95a8e8ea7de9f8a13ca11b519a839cb)

andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin