mem: Add 'controller()' function to NVMInterface.py

As noted here: https://gem5.atlassian.net/browse/GEM5-1133,
NVMInterface.py does not have a `controller()` function, which is used
by `configs/common/MemConfig.py` to obtain a memory controller for a
specific memory type selected. This patch adds a `controller()`
function to `NVNInterface.py` to avoid the reported error.

It should be noted that we do not enforce a rule that a memory type
must include a `controller()` function. `se.py`, and other scrips
that use `configs/common/MemConfigs.py`, should not rely on this
false assumption.

Change-Id: Ieba62f803d3b9f9c5c3c863d5a8c4ca16c5e5e82
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/54923
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
1 file changed