* cipher/poly1305.c (poly1305_default_ops): Move to the top.  Add
prototypes and compile only if USE_SSE2 is not defined.
(poly1305_init_ext_ref32): Compile only if USE_SSE2 is not defined.
(poly1305_blocks_ref32): Ditto.
(poly1305_finish_ext_ref32): Ditto.