Use crypto sp as attestation sp crypto provider

Refactors attestation/opteesp deployment to discover and use
the crypto service provided by an external service endpoint
reachable over FFA.  This is currently hardcoded to use the
crypto SP but making this configurable is straight forward
with this change.

Signed-off-by: Julian Hall <julian.hall@arm.com>
Change-Id: I24a1373997e7cff70844a732b89e9917937f59c2
4 files changed