KVM: s390: Vector exceptions

A new exception type for vector instructions is introduced with
the new processor, but is handled exactly like a Data Exception
which is already handled by the system.

Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>