Avoid clearing memory for CCW-type re-ipl within a logical
partition. This can save a significant amount of time if a logical
partition contains a lot of memory.

On the other hand we still clear memory if running within a second
level hypervisor, since the hypervisor can simply free all memory that
was used for the guest.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>