crypto: Don't define ISRCRY_FAST_TYPE on AMD64
crypto: Don't define ISRCRY_FAST_TYPE on AMD64

- On AMD64, gcc will auto-vectorize the byte-by-byte loops in cbc.c
using the XMM registers, but if we try to be clever using
ISRCRY_FAST_TYPE, it won't.  Define ISRCRY_FAST_TYPE only on 32-bit x86.

cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr