pseries: Update SLOF firmware image

Minor SLOF fixes which are required for libvirtd to function properly:
* vio-vscsi: vscsi-report-luns can return 0
* vio-vscsi: added a proper lun parser
* SLOF: vio-vscsi: fixed bug with reported luns

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alexander Graf <agraf@suse.de>