Use 64-bit FF-A messaging in SPM test SP

The arm-ffa-user driver has been updated to use 64-bit FF-A direct
messaging since v5. Since the NWd test client for the SPM test SP
(xtest) relies on this driver, the SP itself needs to be updated
to stay compatible.

Signed-off-by: Gabor Toth <gabor.toth2@arm.com>
Change-Id: I1312ec0a6ba27b84a1eff596898c6b5cecb80ef0
1 file changed