ACPI: add device_driver and hepler functions

Add device_driver into acpi_driver for driver model.
Add helper functions 'to_acpi_device' and 'to_acpi_driver'
to get structure acpi_device/acpi_driver by device/device_driver.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/scan.c

@@ -222,11 +222,6 @@ acpi_eject_store(struct acpi_device *device, const char *buf, size_t count)
 /* --------------------------------------------------------------------------
 			ACPI Bus operations
    -------------------------------------------------------------------------- */
-static inline struct acpi_device * to_acpi_device(struct device * dev)
-{
-	return container_of(dev, struct acpi_device, dev);
-}
-
 static int root_suspend(struct acpi_device * acpi_dev, pm_message_t state)
 {
 	struct acpi_device * dev, * next;

include/acpi/acpi_bus.h

@@ -136,6 +136,7 @@ struct acpi_driver {
 	atomic_t references;
 	char *ids;		/* Supported Hardware IDs */
 	struct acpi_device_ops ops;
+	struct device_driver drv;
 };
 
 /*
@@ -301,6 +302,8 @@ struct acpi_device {
 };
 
 #define acpi_driver_data(d)	((d)->driver_data)
+#define to_acpi_device(d)	container_of(d, struct acpi_device, dev)
+#define to_acpi_driver(d)	container_of(d, struct acpi_driver, drv)
 
 /*
  * Events