ubuntu_kvm_smoke_test failed with "libvirt: unsupported configuration: machine type 'pseries-mantic' does not support ACPI" on M-6.5 P9

[Po-Hsu Lin]

This issue can be found on P9 node baltar since 6.5.0-33.33 when we add this node back into the pool.

uvt-kvm command complains about:
  uvt-kvm: error: libvirt: unsupported configuration: machine type 'pseries-mantic' does not support ACPI

Test log:
 Running 'sudo -u ubuntu /home/ubuntu/autotest/client/tests/ubuntu_kvm_smoke_test/the-test ppc64el'
 + SUT=bjf-test
 + SSH_KEY=/home/ubuntu/.ssh/id_rsa
 + SSH_OPTIONS='-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=quiet -i /home/ubuntu/.ssh/id_rsa'
 ++ lsb_release -c
 ++ awk '{print$2}'
 + DISTRO=mantic
 + ARCHITECTURE=ppc64el
 + trap cleanup EXIT
 + '[' -z ppc64el ']'
 + kvm-ok
 INFO: /dev/kvm exists
 KVM acceleration can be used
 + '[' 0 '!=' 0 ']'
 + set -e
 + '[' '!' -f /home/ubuntu/.ssh/id_rsa ']'
 + ssh-keygen -f /home/ubuntu/.ssh/id_rsa -t rsa -N ''
 Generating public/private rsa key pair.
 Your identification has been saved in /home/ubuntu/.ssh/id_rsa
 Your public key has been saved in /home/ubuntu/.ssh/id_rsa.pub
 The key fingerprint is:
 SHA256:Tp/PIfr8gMY7XDqCuhcfKPuAmKdVtT7Pl9Uo3D400x8 ubuntu@baltar
 The key's randomart image is:
 +---[RSA 3072]----+
 | |
 | |
 | . |
 | . . |
 | ... S. . + |
 |.o..o..+ o+.B oE |
 |+ +o +oo=o=*.o ..|
 | +..o o==+o=o. .|
 |. o=. .==o.+. |
 +----[SHA256]-----+
 + '[' ppc64el = ppc64el ']'
 + sudo ppc64_cpu --smt=off
 ++ grep -P 'mantic.*ppc64el'
 ++ uvt-simplestreams-libvirt query
 ++ true
 + image=
 + '[' -z '' ']'
 + uvt-simplestreams-libvirt sync --source http://cloud-images.ubuntu.com/daily release=mantic arch=ppc64el
 + uvt-kvm create bjf-test release=mantic arch=ppc64el
 uvt-kvm: error: libvirt: unsupported configuration: machine type 'pseries-mantic' does not support ACPI
 + cleanup
 + uvt-kvm destroy bjf-test