rk: add SPDX license identifier to files with no license

Change-Id: I754250669891307b0deab2bdab1bd01512713f79
Signed-off-by: Tao Huang <huangtao@rock-chips.com>
diff --git a/include/dt-bindings/sensor-dev.h b/include/dt-bindings/sensor-dev.h
old mode 100755
new mode 100644
index 1533243..e03f002
--- a/include/dt-bindings/sensor-dev.h
+++ b/include/dt-bindings/sensor-dev.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 
 #ifndef __DT_BINDINGS_ROCKCHIP_SENSORDEV_H__
 #define __DT_BINDINGS_ROCKCHIP_SENSORDEV_H__