QEMU lists deprecated system call numbers in for Aarch64. These
are never enabled for Linux kernel, so don't define them in Qemu
either. Remove the ifdef around host_to_target_stat64 since
all architectures need it now.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>