fix device mapper issues

As reported on:
https://www.redhat.com/archives/libvir-list/2020-August/msg00236.html
https://www.redhat.com/archives/libvir-list/2020-August/msg00592.html
- virdevmapper-Don-t-cache-device-mapper-major.patch
- virdevmapper-Ignore-all-errors-when-opening-dev-mapper-co.patch
- virdevmapper-Handle-kernel-without-device-mapper-support.patch