Build: Add option to set NS Evaluation App path

This commit adds the option to leverage TF-M build system for simple
evaluation projects. It allows to set an out-of-tree NS application.

Change-Id: Iee6fd1a7561d332e21b06dd9d38d7382840da787
Signed-off-by: Gabor Abonyi <gabor.abonyi@arm.com>
2 files changed