[ARM] Add more syscalls

[ARM] Add more syscalls

Add:
  sys_unshare
  sys_set_robust_list
  sys_get_robust_list
  sys_splice
  sys_arm_sync_file_range
  sys_tee
  sys_vmsplice
  sys_move_pages
  sys_getcpu

Special note about sys_arm_sync_file_range(), which is implemented as:

asmlinkage long sys_arm_sync_file_range(int fd, unsigned int flags,
                                        loff_t offset, loff_t nbytes)
{
        return sys_sync_file_range(fd, offset, nbytes, flags);
}

We can't export sys_sync_file_range() directly on ARM because the
argument list someone picked does not fit in the available registers.
Would be nice if... there was an arch maintainer review mechanism for
new syscalls before they hit the kernel.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>