* src/gcrypt.h.in (GCRY_KEM_RAW_X448, GCRY_KEM_DHKEM448): New.
* cipher/kem-ecc.c (_gcry_ecc_raw_encap): Support X448.
(ecc_dhkem_kdf, _gcry_ecc_dhkem_encap): Likewise.
(_gcry_ecc_dhkem_decap): Likewise.
* cipher/kem.c (_gcry_kem_keypair): Add support for GCRY_KEM_RAW_X448
and GCRY_KEM_DHKEM448.
(_gcry_kem_encap, _gcry_kem_decap): Likewise.