[S390] head.S code moving.

There is almost no room left for any new code between 0x10000
and 0x10480. Move the code from 0x10000 to 0x11000.

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