[media] diff-v4l.rst: Make capabilities table fit in LaTeX

This table has several troubles:
	- a duplicated "struct" on its name;
	- a reference to a V4L version 1 struct that will never
	  point to something (as we got rid of V4L1 API a long
	  time ago);
	- misses hints for LaTeX output (column size and longtable
	  style).

Fix them.

It should be noticed that the first column of this table is
not aligned with the rest. I suspect that this is a bug at
the flat-table extension.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/media/uapi/v4l/diff-v4l.rst

@@ -95,7 +95,9 @@ and radio devices supporting a set of related functions like video
 capturing, video overlay and VBI capturing. See :ref:`open` for an
 introduction.
 
+.. tabularcolumns:: |p{5.5cm}|p{6.5cm}|p{5.5cm}
 
+.. cssclass:: longtable
 
 .. flat-table::
     :header-rows:  1
@@ -104,7 +106,7 @@ introduction.
 
     -  .. row 1
 
-       -  struct :c:type:`struct video_capability` ``type``
+       -  ``struct video_capability`` ``type``
 
        -  struct :ref:`v4l2_capability <v4l2-capability>`
 	  ``capabilities`` flags