* cipher/blake2.c (DEFINE_BLAKE2_VARIANT): Add hash_buffer and
hash_buffers functions for BLAKE2 variants.
* cipher/keccak.c (_gcry_sha3_hash_buffer, _gcry_sha3_hash_buffers)
(_gcry_sha3_224_hash_buffer, _gcry_sha3_224_hash_buffers)
(_gcry_sha3_256_hash_buffer, _gcry_sha3_256_hash_buffers)
(_gcry_sha3_384_hash_buffer, _gcry_sha3_384_hash_buffers)
(_gcry_sha3_512_hash_buffer, _gcry_sha3_512_hash_buffers): New.
* cipher/sha256.c (_gcry_sha224_hash_buffer)
(_gcry_sha224_hash_buffers): New.
* cipher/sha512.c (_gcry_sha384_hash_buffer)
(_gcry_sha384_hash_buffers): New.