ACPI: Add .setup() and .cleanup() callbacks to struct acpi_bus_type

Add two new callbacks,.setup() and .cleanup(), struct acpi_bus_type
and modify acpi_platform_notify() to call .setup() after executing
acpi_bind_one() successfully and acpi_platform_notify_remove() to
call .cleanup() before running acpi_unbind_one().  This will allow
the users of struct acpi_bus_type, PCI in particular, to specify
operations to be executed right after the given device has been
associated with a companion struct acpi_device and right before
it's going to be detached from that companion, respectively.

The main motivation is to be able to get rid of acpi_pci_bind()
and acpi_pci_unbind(), which are horrible horrible stuff.  [In short,
there are three problems with them: The way they populate the .bind()
and .unbind() callbacks of ACPI devices is rather less than
straightforward, they require special hotplug-specific paths to be
present in the ACPI namespace scanning code and by the time
acpi_pci_unbind() is called the PCI device object in question may
not exist any more.]

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>

include/acpi/acpi_bus.h

@@ -383,6 +383,8 @@ struct acpi_bus_type {
 	int (*find_device) (struct device *, acpi_handle *);
 	/* For bridges, such as PCI root bridge, IDE controller */
 	int (*find_bridge) (struct device *, acpi_handle *);
+	void (*setup)(struct device *);
+	void (*cleanup)(struct device *);
 };
 int register_acpi_bus_type(struct acpi_bus_type *);
 int unregister_acpi_bus_type(struct acpi_bus_type *);