tripleo-validations: update "overcloud" to "allovercloud"

[Cédric Jeanneret]

We need to update the "hosts" value of a fair amount of validations:
for some time now, the "overcloud" group doesn't exist anymore, since it's now <stackname>_overcloud.
The best replacement is "allovercloud".

We need to backport the following patch down to stable/train:
https://review.opendev.org/744922

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/ussuri
Review: https://review.opendev.org/745787

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/train
Review: https://review.opendev.org/745788

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/745787
Committed: https://git.openstack.org/cgit/openstack/tripleo-validations/commit/?id=b7d679d936d40708d0ce996161de42389eca6bea
Submitter: Zuul
Branch: stable/ussuri

commit b7d679d936d40708d0ce996161de42389eca6bea
Author: Cédric Jeanneret <email address hidden>
Date: Wed Aug 5 16:55:14 2020 +0200

    Updated "overcloud" to "allovercloud" group

    Apparently this is the new term to access all the overcloud nodes.

    Closes-Bug: #1891267
    Change-Id: I07fd17501ea66d229549fcf4031ae4126b055906
    (cherry picked from commit 1a4991daf38d61e453ae4d948e7e639f52986943)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/745788
Committed: https://git.openstack.org/cgit/openstack/tripleo-validations/commit/?id=015dab217e946355f7a249f174c67a85a6b679d8
Submitter: Zuul
Branch: stable/train

commit 015dab217e946355f7a249f174c67a85a6b679d8
Author: Cédric Jeanneret <email address hidden>
Date: Wed Aug 5 16:55:14 2020 +0200

    Updated "overcloud" to "allovercloud" group

    Apparently this is the new term to access all the overcloud nodes.

    Closes-Bug: #1891267
    Change-Id: I07fd17501ea66d229549fcf4031ae4126b055906
    (cherry picked from commit 1a4991daf38d61e453ae4d948e7e639f52986943)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/tripleo-validations 11.4.0 release.