[media] videodev2.h: add SMPTE 2084 transfer function define

CEA-861.3 adds support for the SMPTE 2084 Electro-Optical Transfer Function
as can be used in HDR displays. Add a define for this in videodev2.h.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

include/uapi/linux/videodev2.h

@@ -269,6 +269,7 @@ enum v4l2_xfer_func {
 	V4L2_XFER_FUNC_SMPTE240M   = 4,
 	V4L2_XFER_FUNC_NONE        = 5,
 	V4L2_XFER_FUNC_DCI_P3      = 6,
+	V4L2_XFER_FUNC_SMPTE2084   = 7,
 };
 
 /*