crypto/hash-gcrypt: Implement new hash API

crypto/hash-gcrypt: Implement new hash API

Implements the new hashing API in the gcrypt hash driver.
Supports creating/destroying a context, updating the context
with input data and obtaining an output hash.

Signed-off-by: Alejandro Zeise <alejandro.zeise@seagate.com>
[ clg: - Dropped qcrypto_hash_supports() in qcrypto_gcrypt_hash_new()
       - Reworked qcrypto_gcrypt_hash_finalize()
       - Handled gcry_md_open() errors in qcrypto_gcrypt_hash_new()
       - Checkpatch fixes ]
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>