Enable psa-acs pre-fetching support

psa-acs added support for using pre-fetched QCBOR source code. Adapt
the TS build system to allow using this feature.

Change-Id: I9c7019d3ad2f522ad2ebeda79c447f25a82f1bfe
Signed-off-by: Gyorgy Szing <Gyorgy.Szing@arm.com>
5 files changed