mem: Add tryTiming suppport to CommMonitor

mem: Add tryTiming suppport to CommMonitor

The CommMonitor did not support tryTiming, which resulted in gem5
panicing if the CommMonitor was used.

With this change, we update the CommMonitor pass through the
tryTiming() calls.

Change-Id: I86810170e5e10a0c5d63af76fc4a6ab70710d2fb
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15736
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>