media: v4l: link dt-bindings and uapi

Since we expose the definition to the dt-bindings we need to keep those
definitions in sync. To address this the patch adds a simple cross
reference to the dt-bindings.
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

include/uapi/linux/videodev2.h

@@ -1242,6 +1242,10 @@ struct v4l2_selection {
 
 typedef __u64 v4l2_std_id;
 
+/*
+ * Attention: Keep the V4L2_STD_* bit definitions in sync with
+ * include/dt-bindings/display/sdtv-standards.h SDTV_STD_* bit definitions.
+ */
 /* one bit for each */
 #define V4L2_STD_PAL_B          ((v4l2_std_id)0x00000001)
 #define V4L2_STD_PAL_B1         ((v4l2_std_id)0x00000002)