ACPI / glue: Add .match() callback to struct acpi_bus_type

USB uses the .find_bridge() callback from struct acpi_bus_type
incorrectly, because as a result of the way it is used by USB every
device in the system that doesn't have a bus type or parent is
passed to usb_acpi_find_device() for inspection.

What USB actually needs, though, is to call usb_acpi_find_device()
for USB ports that don't have a bus type defined, but have
usb_port_device_type as their device type, as well as for USB
devices.

To fix that replace the struct bus_type pointer in struct
acpi_bus_type used for matching devices to specific subsystems
with a .match() callback to be used for this purpose and update
the users of struct acpi_bus_type, including USB, accordingly.
Define the .match() callback routine for USB, usb_acpi_bus_match(),
in such a way that it will cover both USB devices and USB ports
and remove the now redundant .find_bridge() callback pointer from
usb_acpi_bus.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>

include/acpi/acpi_bus.h

@@ -437,7 +437,8 @@ void acpi_remove_dir(struct acpi_device *);
  */
 struct acpi_bus_type {
 	struct list_head list;
-	struct bus_type *bus;
+	const char *name;
+	bool (*match)(struct device *dev);
 	/* For general devices under the bus */
 	int (*find_device) (struct device *, acpi_handle *);
 	/* For bridges, such as PCI root bridge, IDE controller */