config, arm: memoryMode test

config, arm: memoryMode test

Commit 9a13acaa367769c38859342de9bc35aac59a6710 doesn't comply with the
same behaviour. The conditional test the memory mode on the same cluster,
while it should test the other cluster.

Change-Id: If3a7863f0905e66a548001d8e74689f5dd07179c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17748
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>