dist, dev: fix etherswitch upgrade script

The aforementioned upgrader in [1] assumes every option in [system]
has a delimiting '.', and also seems to do its rewriting work a bit too
unconditionally. Most checkpoints in the wild don't have this device,
in which case this script should be a safe no-op.

[1] 2aa4d7b dist, dev: Fixed the packet ordering in etherswitch

Change-Id: Icfd0350985109df1628eb9ab864cda42c54060a8
Reviewed-by: Gabor Dozsa <gabor.dozsa@arm.com>

dist, dev: Fixed the packet ordering in etherswitch

This patch fixes the order that packets gets pushed into the output fifo
of etherswitch. If two packets arrive at the same tick to the etherswitch,
we sort and push them based on their source port id.
In dist-gem5 simulations, if there is no ordering inforced while two
packets arrive at the same tick, it can lead to non-deterministic simulations

Committed by Jason Lowe-Power <power.jg@gmail.com>