Build: Move 'secure_fw' out of 'app' build territory

'secure_fw' should be a standalone project instead of
being launched by 'app' build. Move it out of 'app'
territory and correct veneer lib settings for 'app'.

Change-Id: Ic50b0df234cbee0741ff9385a0c59ef87070df41
Signed-off-by: Ken Liu <ken.liu@arm.com>
3 files changed