* cipher/cipher-gcm-ppc.c (ALIGNED_16): New.
(vec_store_he, vec_load_he): Remove WORDS_BIGENDIAN ifdef.
(vec_dup_byte_elem): New.
(_gcry_ghash_setup_ppc_vpmsum): Match function declaration with
prototype in cipher-gcm.c; Load C2 with VEC_LOAD_BE; Use
vec_dup_byte_elem; Align constants to 16 bytes.
(_gcry_ghash_ppc_vpmsum): Match function declaration with
prototype in cipher-gcm.c; Align constant to 16 bytes.
* cipher/cipher-gcm.c (ghash_ppc_vpmsum): Return value from
_gcry_ghash_ppc_vpmsum.
* cipher/cipher-internal.h (GCM_USE_PPC_VPMSUM): Remove requirement
for !WORDS_BIGENDIAN.