PCI: hotplug: acpiphp: avoid acpiphp "cannot get bridge info" PCI hotplug failure

On some systems, the ACPI bus check event can reference a bridge that is
higher in the ACPI hierarchy than the bridge immediately above the
hotplug PCI slot into which an adapter was just inserted.  The current
'acpiphp' code expects the bus check event to reference the bridge
immediately above the slot that received the adapter so the hotplug
operation can fail on these systems with the message "acpiphp_glue:
cannot get bridge info".  This change fixes the problem by
re-enumerating all slots that lie below the bridge referenced by the bus
check event, including those slots that may be located under lower level
PCI-to-PCI bridge(s).

Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Cc: <lcm@us.ibm.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>