s390x/pci: let intercept devices have separate PCI groups

s390x/pci: let intercept devices have separate PCI groups

Let's use the reserved pool of simulated PCI groups to allow intercept
devices to have separate groups from interpreted devices as some group
values may be different. If we run out of simulated PCI groups, subsequent
intercept devices just get the default group.
Furthermore, if we encounter any PCI groups from hostdevs that are marked
as simulated, let's just assign them to the default group to avoid
conflicts between host simulated groups and our own simulated groups.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20220902172737.170349-7-mjrosato@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>