qemu: hotplug: Allow marking unplugged devices by alias
qemu: hotplug: Allow marking unplugged devices by alias

Add a overlay function that takes the alias directly rather than
extracting it from a device info.

olafhering/libvirt,taget/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,crobinso/libvirt,taget/libvirt,datto/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,jfehlig/libvirt,zippy2/libvirt,eskultety/libvirt,fabianfreyer/libvirt,crobinso/libvirt,olafhering/libvirt,zippy2/libvirt,andreabolognani/libvirt,eskultety/libvirt,jfehlig/libvirt,jfehlig/libvirt,libvirt/libvirt,andreabolognani/libvirt,datto/libvirt,olafhering/libvirt,nertpinx/libvirt,datto/libvirt,libvirt/libvirt,datto/libvirt,VenkatDatta/libvirt,taget/libvirt,VenkatDatta/libvirt,crobinso/libvirt,eskultety/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,olafhering/libvirt,fabianfreyer/libvirt,taget/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,eskultety/libvirt,jardasgit/libvirt,crobinso/libvirt,libvirt/libvirt,jfehlig/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,zippy2/libvirt,libvirt/libvirt,jardasgit/libvirt,taget/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,eskultety/libvirt,nertpinx/libvirt,zippy2/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,datto/libvirt