This fixes the two failures in test_suite_x509parse when both
ECP_RESTARTABLE and USE_PSA_CRYPTO are enabled.
The failure happened because the operation is dispatched to PSA when
restart is disabled (max_ops == 0).
Previously it was correct for this test function not to initialize PSA,
because it depends on ECP_RESTARTABLE which used to conflict with
USE_PSA_CRYPTO, but that's no longer the case.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>