[PATCH] pciehp: Implement get_address callback

This patch implements .get_address callback of hotplug_slot_ops for
PCIEHP driver. With this patch, we can see bus address of hotplug
slots as follows:

	# cat /sys/bus/pci/slots/0010_0000/address
	0000:0a:00

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Cc: Kristen Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>