s390: remove "64" suffix from a couple of files

Rename a couple of files to get rid of the "64" suffix.
"git blame" will still work.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
6 files changed