After this, only PK, X.509 and TLS remain to be done.
Deterministic uses HMAC-DRBG which uses MD, so it needs crypto_init()
when using a driver-only hash.
Also, remove a special-purpose macro that's no longer needed.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>