ruby, arm: Forward invalidations to the local exclusive monitor

ruby, arm: Forward invalidations to the local exclusive monitor

ARM systems require local exclusive monitors for the implementation of
synchronization primitives between processors. A ruby memory system
needs to forward invalidations to the local exclusive monitors to
to correctly determine their state.

Change-Id: I7bc4d0f2a5be0f4e36a25c87aa4a81a3f086fb3c
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2904
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>