ACPI / dock / PCI: Drop ACPI dock notifier chain

The only user of the ACPI dock notifier chain is the ACPI-based PCI
hotplug (acpiphp) driver that uses it to carry out post-dock fixups
needed by some systems with broken _DCK.  However, it is not
necessary to use a separate notifier chain for that, as it can be
simply replaced with a new callback in struct acpi_dock_ops.

For this reason, add a new .fixup() callback to struct acpi_dock_ops
and make hotplug_dock_devices() execute it for all dock devices with
hotplug operations registered.  Accordingly, make acpiphp point that
callback to the function carrying out the post-dock fixups and
do not register a separate dock notifier for each device
registering dock operations.  Finally, drop the ACPI dock notifier
chain that has no more users.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

include/acpi/acpi_drivers.h

@@ -113,14 +113,13 @@ void pci_acpi_crs_quirks(void);
                                   Dock Station
   -------------------------------------------------------------------------- */
 struct acpi_dock_ops {
+	acpi_notify_handler fixup;
 	acpi_notify_handler handler;
 	acpi_notify_handler uevent;
 };
 
 #ifdef CONFIG_ACPI_DOCK
 extern int is_dock_device(acpi_handle handle);
-extern int register_dock_notifier(struct notifier_block *nb);
-extern void unregister_dock_notifier(struct notifier_block *nb);
 extern int register_hotplug_dock_device(acpi_handle handle,
 					const struct acpi_dock_ops *ops,
 					void *context,
@@ -132,13 +131,6 @@ static inline int is_dock_device(acpi_handle handle)
 {
 	return 0;
 }
-static inline int register_dock_notifier(struct notifier_block *nb)
-{
-	return -ENODEV;
-}
-static inline void unregister_dock_notifier(struct notifier_block *nb)
-{
-}
 static inline int register_hotplug_dock_device(acpi_handle handle,
 					       const struct acpi_dock_ops *ops,
 					       void *context,