[media] Documentation: fix outdated statement re. v4l2

Fix tense used for describing struct v4l2_fh as it has been added a
while ago.

Signed-off-by: Nicolas Thery <nicolas.thery@st.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Documentation/video4linux/v4l2-framework.txt

@@ -68,8 +68,7 @@ Structure of the framework
 The framework closely resembles the driver structure: it has a v4l2_device
 struct for the device instance data, a v4l2_subdev struct to refer to
 sub-device instances, the video_device struct stores V4L2 device node data
-and in the future a v4l2_fh struct will keep track of filehandle instances
-(this is not yet implemented).
+and the v4l2_fh struct keeps track of filehandle instances.
 
 The V4L2 framework also optionally integrates with the media framework. If a
 driver sets the struct v4l2_device mdev field, sub-devices and video nodes