Out-of-tree build support
Open, Needs TriagePublic

Description

The current requirement of the out-of-tree build is that:
The generated files by tools/tfm_parse_manifest_list.py can take custom manifests and generate files out of TF-M source tree
And then the build system can use the generated files outside TF-M to build.

The change for the tools: https://review.trustedfirmware.org/c/trusted-firmware-m/+/2606