linux-user: AArch64 has sync_file_range, not sync_file_range2

The AArch64 Linux ABI syscall 84 is sync_file_range, not
sync_file_range2 (in the kernel it uses the asm-generic
headers and does not define __ARCH_WANT_SYNC_FILE_RANGE2).
Update our TARGET_NR_* definitions accordingly.

This fixes the sync_file_range syscall which otherwise
gets its arguments in the wrong order.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>