ACPI: save device_type in acpi_device

Most uses of the ACPI bus device_type (ACPI_BUS_TYPE_DEVICE,
ACPI_BUS_TYPE_POWER, etc) are during device initialization, but
we do need it later for notify handler installation, since that
is different for fixed hardware devices vs. namespace devices.

This patch saves the device_type in the acpi_device structure,
so we can check that rather than comparing against the _HID string.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/scan.c

@@ -1240,6 +1240,7 @@ acpi_add_single_object(struct acpi_device **child,
 		return -ENOMEM;
 	}
 
+	device->device_type = type;
 	device->handle = handle;
 	device->parent = parent;
 	device->bus_ops = *ops; /* workround for not call .start */

include/acpi/acpi_bus.h

@@ -262,7 +262,8 @@ struct acpi_device_wakeup {
 /* Device */
 
 struct acpi_device {
-	acpi_handle handle;
+	int device_type;
+	acpi_handle handle;		/* no handle for fixed hardware */
 	struct acpi_device *parent;
 	struct list_head children;
 	struct list_head node;