s390/kernel: Update /proc/sysinfo file with Extended Name and UUID

A new architecture extends STSI 3.2.2 with UUID and long names. KVM
will provide the first implementation. This patch adds the additional
data  fields (Extended Name and UUID) from the 4KB block returned by
the STSI 3.2.2 command and reflect this information in the
/proc/sysinfo file accordingly.

Signed-off-by: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>