Populate FVP YAML files for cortex-a57x4 and cortex-a57x-a53x models

FVP YAML file generation is a two step process: 1. yaml template
creation and 2. fvp values replacement on template created by 1. This
patch only relates to 2 and specifically for 'cortex-a53x4' and
'cortex-a57x-a53x' models.

Signed-off-by: Leonardo Sandoval <leonardo.sandoval@linaro.org>
Change-Id: If04d5ad8b07831bbbfcc01aede0c475c7dddf99c
4 files changed