rdfremontcfg2/run_model: fix virtio_net params

Virtio Net device parameter should be pointing to the Chip 0's Rest of
the System (RoS). Update the model param to point to rss0.

Reported-by: Vivek Gautam <vivek.gautam@arm.com>
Signed-off-by: Vijayenthiran Subramaniam <vijayenthiran.subramaniam@arm.com>
Change-Id: I0ab5dedb7e88f9a7fa74f7c48a8e159efe07f063