We now take the subchannel set id also into account to find the boot device.
If we want to use a subchannel set other than the default set 0, we first
need to enable the mss facility.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>