device property: Constify device_get_match_data()

Constify device_get_match_data() as OF and ACPI variants return
constant value.

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/base/property.c b/drivers/base/property.c
index 3022362..8f205f6 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -1410,9 +1410,8 @@
 }
 EXPORT_SYMBOL(fwnode_graph_parse_endpoint);
 
-void *device_get_match_data(struct device *dev)
+const void *device_get_match_data(struct device *dev)
 {
-	return fwnode_call_ptr_op(dev_fwnode(dev), device_get_match_data,
-				  dev);
+	return fwnode_call_ptr_op(dev_fwnode(dev), device_get_match_data, dev);
 }
 EXPORT_SYMBOL_GPL(device_get_match_data);