Fedora doesn't ship OVMF/AAVMF builds in its repos due to licensing
issues, so the recommended way to consume these bits is via Gerd's
nightly repo: https://www.kraxel.org/repos

Let's teach fedora builds about the loader/nvram pairs these packages
installed, so users don't need to edit qemu.conf to get virt-manager
UEFI support.