Let us update the existing xml and replies files for QEMU 2.12.0 on
s390x.

Used a z14 using a QEMU 2.12 GA build and the following sequence:

  tests/qemucapsprobe /usr/bin/qemu-system-s390x > \
         tests/qemucapabilitiesdata/caps_2.12.0.s390x.replies

  VIR_TEST_REGENERATE_OUTPUT=1 tests/qemucapabilitiestest
  VIR_TEST_REGENERATE_OUTPUT=1 tests/domaincapstest
Signed-off-by: NShalini Chellathurai Saroja <shalini@linux.vnet.ibm.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>