rde1edge/run_model: align to changes in SCP/MCP firmware names

The SCP firmware binary names are now changed to *cp_romfw.bin and
*cp_ramfw.bin. Align to these changes in the run_model script.

Change-Id: I6bacda28fb2252cdde7f905f6bf9e796402947df
Signed-off-by: Thomas Abraham <thomas.abraham@arm.com>