V4L/DVB (9897): v4l2: Add camera zoom controls

The zoom controls move the zoom lens group to a an absolute position, as a
relative displacement or at a given speed until reaching physical device
limits. Positive values move the zoom lens group towards the telephoto
direction, negative values towards the wide-angle direction.
Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

include/linux/videodev2.h

@@ -1118,6 +1118,10 @@ enum  v4l2_exposure_auto_type {
 #define V4L2_CID_FOCUS_RELATIVE			(V4L2_CID_CAMERA_CLASS_BASE+11)
 #define V4L2_CID_FOCUS_AUTO			(V4L2_CID_CAMERA_CLASS_BASE+12)
 
+#define V4L2_CID_ZOOM_ABSOLUTE			(V4L2_CID_CAMERA_CLASS_BASE+13)
+#define V4L2_CID_ZOOM_RELATIVE			(V4L2_CID_CAMERA_CLASS_BASE+14)
+#define V4L2_CID_ZOOM_CONTINUOUS		(V4L2_CID_CAMERA_CLASS_BASE+15)
+
 /*
  *	T U N I N G
  */