s390x: smp: Test all CRs on initial reset

All CRs are set to 0 and CRs 0 and 14 are set to pre-defined values,
so we also need to test 1-13 and 15 for 0.

And while we're at it, let's also set some values to cr 1, 7 and 13, so
we can actually be sure that they will be zeroed.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200424093356.11931-1-frankja@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>