ACPI: attach thermal zone info

Intel menlow driver needs to get the pointer of themal_zone_device
structure of an ACPI thermal zone.
Attach this to each ACPI thermal zone device object.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Thomas Sujith <sujith.thomas@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 1b4cf98..8df325d 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -122,6 +122,31 @@
 
 EXPORT_SYMBOL(acpi_bus_get_status);
 
+void acpi_bus_private_data_handler(acpi_handle handle,
+				   u32 function, void *context)
+{
+	return;
+}
+EXPORT_SYMBOL(acpi_bus_private_data_handler);
+
+int acpi_bus_get_private_data(acpi_handle handle, void **data)
+{
+	acpi_status status = AE_OK;
+
+	if (!*data)
+		return -EINVAL;
+
+	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
+	if (ACPI_FAILURE(status) || !*data) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
+				handle));
+		return -ENODEV;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(acpi_bus_get_private_data);
+
 /* --------------------------------------------------------------------------
                                  Power Management
    -------------------------------------------------------------------------- */