Add support for the VMULL.P64 polynomial 64x64 to 128 bit multiplication
instruction in the A32/T32 instruction sets; this is part of the v8
Crypto Extensions.

To do this we have to move the neon_pmull_64_{lo,hi} helpers from
helper-a64.c into neon_helper.c so they can be used by the AArch32
translator.
Inspired-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1401386724-26529-4-git-send-email-peter.maydell@linaro.org