platforms/sgiclarka: add model launch script for SGI-Clark.Ares platform

Add a helper script to script to launch the model for SGI-Clark.Ares
platform. This script sets up the model parameters based on the input
parameters it receives.

Change-Id: I833bdaae8e7e2a36b4ab33771801da59ba510f12
Signed-off-by: Chandni Cherukuri <chandni.cherukuri@arm.com>