PCI: more fixes for PCIe Hotplug so that it works with ExpressCard slots on Dell notebooks (and others?) in conjunction with modparam of pciehp_force=1

Split out the hotplug hardware initialization code from pcie_init()
into pcie_init_enable_events(), without changing any functionality.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>