[PATCH] acpiphp: add dock event handling

These patches add generic dock event handling to acpiphp.  If there are
pci devices that need to be inserted/removed after the dock event, the
event notification will be handed down to the normal pci hotplug event
handler in acpiphp so that new bridges/devices can be enumerated.

Because some dock stations do not have pci bridges or pci devices that
need to be inserted after a dock, acpiphp will remain loaded to handle
dock events even if no hotpluggable pci slots are discovered.

You probably need to have the pci=assign-busses kernel parameter enabled
to use these patches, and you may not allow ibm_acpi to handle docking
notifications and use this patch.

This patch incorporates feedback provided by many.

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