* cipher/rijndael-ppc.c (ROUND_KEY_VARIABLES, PRELOAD_ROUND_KEYS)
(AES_ENCRYPT, AES_DECRYPT): New.
(_gcry_aes_ppc8_prepare_decryption): Rename to...
(aes_ppc8_prepare_decryption): ... this.
(_gcry_aes_ppc8_prepare_decryption): New.
(aes_ppc8_encrypt_altivec, aes_ppc8_decrypt_altivec): Remove.
(_gcry_aes_ppc8_encrypt): Use AES_ENCRYPT macro.
(_gcry_aes_ppc8_decrypt): Use AES_DECRYPT macro.
(_gcry_aes_ppc8_ocb_crypt): Uncomment; Optimizations for OCB offset
calculations, etc; Use new load/store and encryption/decryption macros.
* cipher/rijndaelc [USE_PPC_CRYPTO] (_gcry_aes_ppc8_ocb_crypt): New
prototype.
(do_setkey, _gcry_aes_ocb_crypt) [USE_PPC_CRYPTO]: Add PowerPC AES OCB
encryption/decryption.

 OCB enc |      2.33 ns/B     410.1 MiB/s      8.84 c/B
 OCB dec |      2.34 ns/B     407.2 MiB/s      8.90 c/B
OCB auth |      2.32 ns/B     411.1 MiB/s      8.82 c/B

 OCB enc |     0.250 ns/B      3818 MiB/s     0.949 c/B
 OCB dec |     0.250 ns/B      3820 MiB/s     0.949 c/B
OCB auth |      2.31 ns/B     412.5 MiB/s      8.79 c/B