PCI Hotplug: make cpcihp driver use modern apis

This removes the depandancy of the cpcihp driver from the PCI_LEGACY
config option by removing its usage of the pci_find_bus() function.


Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Scott Murray <scottm@somanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>