pseries: Remove PCI device from PCI host bridge code

pseries: Remove PCI device from PCI host bridge code

The sPAPR PCI code defines a PCI device "spapr-pci-host-bridge-pci" which
is never used.  This came over from the earlier bridge driver we used as
a template.  Some other bridges appear on their own PCI bus as a device,
but that is not true of pSeries bridges, which are pure host to PCI with
no visible presence on the PCI side.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>