ACPICA: Add post-order callback to acpi_walk_namespace

The existing interface only has a pre-order callback. This change
adds an additional parameter for a post-order callback which will
be more useful for bus scans. ACPICA BZ 779.

Also update the external calls to acpi_walk_namespace.

http://www.acpica.org/bugzilla/show_bug.cgi?id=779

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/acpica/acnamesp.h b/drivers/acpi/acpica/acnamesp.h
index 09a2764..168e608 100644
--- a/drivers/acpi/acpica/acnamesp.h
+++ b/drivers/acpi/acpica/acnamesp.h
@@ -104,7 +104,8 @@
 		       acpi_handle start_object,
 		       u32 max_depth,
 		       u32 flags,
-		       acpi_walk_callback user_function,
+		       acpi_walk_callback pre_order_visit,
+		       acpi_walk_callback post_order_visit,
 		       void *context, void **return_value);
 
 struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node