rdfremont/run_model.sh: Enable RME, ECV and preload RMM

Enable Realm Management Extension (RME) and Enhanced Counter
Virtualization (ECV) features for RD-Fremont platform and preload Realm
Management Monitor (RMM) as required by TF-A BL31 to carry out
RSI/RMI operations.

Signed-off-by: Sathyam Panda <sathyam.panda@arm.com>
Change-Id: I0a4f3a79352dc5ded51164144b8ea6e96e49fba1