Fix ARM assembly when building __PIC__

* cipher/camellia-arm.S (GET_DATA_POINTER): New.
(_gcry_camellia_arm_encrypt_block): Use GET_DATA_POINTER.
(_gcry_camellia_arm_decrypt_block): Ditto.
* cipher/cast5-arm.S (GET_DATA_POINTER): New.
(_gcry_cast5_arm_encrypt_block, _gcry_cast5_arm_decrypt_block)
(_gcry_cast5_arm_enc_blk2, _gcry_cast5_arm_dec_blk2): Use
GET_DATA_POINTER.
* cipher/rijndael-arm.S (GET_DATA_POINTER): New.
(_gcry_aes_arm_encrypt_block, _gcry_aes_arm_decrypt_block): Use
GET_DATA_POINTER.
--

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
(cherry picked from commit 994c758d8f5471c7e9c38c2834742cca2502d35f)