[qe-core][functional][s390x] Change structure of s390x KVM hosts on production (o.s.d)
with the new Mainframe, QA SLE got a bunch of new LPARs which should be used for production as well as for development
Since those LPARs are now set up on the SUSE-IT level, we can start to integrate them into our environment as well as adapt our tests to make use of them
According to agreements we need to run tests on SLE12SP3 (to be clarified), SLE 12SP4 and SLE15 host systems)
Right now we only have a 12SP3 host in production and a very limited amount of SLE15 hosts.
- Rename current s390-kvm-sle12 to make it clear that it's a 12sp3 host
- Add 12sp4 host to infrastructure