[S390] Convert sys_clone to function with parameters.

Use function parameters instead of accessing the pt_regs structure
to get the parameters.
Also merge the 31 and 64 bit versions since they are identical.

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