* src/cipher-proto.h (gcry_md_hash_buffers_t): Add nbytes parameter
for outbuf size for XOF algorithms.
* cipher/md.c (_gcry_md_hash_buffer)
(_gcry_md_hash_buffers_extract): Adjust for spec->hash_buffers
parameter change.
* cipher/keccak.c (_gcry_sha3_hash_buffers): Add nbytes parameter and
handling for XOF output.
* cipher/blake2.c (DEFINE_BLAKE2_VARIANT): Add nbytes parameter for
hash_buffers.
* cipher/rmd160.c (_gcry_rmd160_hash_buffers): Add nbytes parameter.
* cipher/sha1.c (_gcry_sha1_hash_buffers): Add nbytes parameter.
(_gcry_sha1_hash_buffer): Pass nbytes to _gcry_sha1_hash_buffers.
* cipher/sha256.c (_gcry_sha256_hash_buffers)
(_gcry_sha224_hash_buffers): Add nbytes parameter.
* cipher/sha512.c (_gcry_sha512_hash_buffers)
(_gcry_sha384_hash_buffers, _gcry_sha512_256_hash_buffers)
(_gcry_sha512_224_hash_buffers): Add nbytes parameter.
* cipher/sm3.c (_gcry_sm3_hash_buffers): Add nbytes parameter.