rdinfra/run_model: update the fastmodel names for rdinfra platforms

The RD-N1-Edge and RD-E1-Edge platforms have new names for the fastmodel
binary. Adapt the run-model scripts of these platforms to these changes.

Change-Id: I6d43178ef487656e1b41a42d98f50b3a0d6668a8
Signed-off-by: Thomas Abraham <thomas.abraham@arm.com>