arch-arm: Set CM bit in DataAbort

arch-arm: Set CM bit in DataAbort

The CM bit in a DataAbort ISS indicates whether the Data Abort came from
a cache maintenance or address translation instruction.

Change-Id: I8888520446550581c8dd0507a8989935db7047be
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21305
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>