If we're building aarch64-linux-user then the 32 bit CPUs are
all unwanted, because they can't possibly execute the 64 bit
binaries we will be running; disable them.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1378235544-22290-9-git-send-email-peter.maydell@linaro.org