configs: Add disjoint VIPER configuration

The disjoint VIPER configuration creates completely disconnected CPU and
GPU Ruby networks which can communicate only via the PCI bus. Either
garnet or simple network can be used. This copies most of the Ruby setup
from Ruby.py's create_system since creating disjoint networks is not
possible using Ruby.py.

Change-Id: Ibc23aa592f56554d088667d8e309ecdeb306da68
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/53072
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
4 files changed