qemu.tests.pci_devices: Test fixup and update

Hi guys,

this patchset fixes some issues of `pci_devices` test and adds support for new device types. Also the configuration was rewritten because some setups were impossible in real life and will not be supported in kernel (at least for now).

Kind regards,
Lukáš Doktor

PS: The last configuration is still not approved, I'm still waiting for the developer. But it's not easy to catch him so in case it's a bad setup, I'll remove/modify it later.