s390: do not touch sie64a.S with duplicate include removal

This is a partial revert of  e44ba033 ("treewide: remove duplicate
includes").

The file is gone in s390 tree and will not exist any more.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>