[media] Fix videodev.h references at the V4L DocBook

      <varlistentry>

	<term><parameter>request</parameter></term>

	<listitem>

	  <para>V4L2 ioctl request code as defined in the <link

linkend="videodev">videodev.h</link> header file, for example

	  <para>V4L2 ioctl request code as defined in the <filename>videodev2.h</filename> header file, for example

VIDIOC_QUERYCAP.</para>

	</listitem>

      </varlistentry>

in it whether the argument is an input, output or read/write

parameter, and the size of the argument <parameter>argp</parameter> in

bytes. Macros and defines specifying V4L2 ioctl requests are located

in the <link linkend="videodev">videodev.h</link> header file.

in the <filename>videodev2.h</filename> header file.

Applications should use their own copy, not include the version in the

kernel sources on the system they compile on. All V4L2 ioctl requests,

their respective function and parameters are specified in <xref

has just as many pad bytes after it as the other rows.</para>

    <para>In V4L2 each format has an identifier which looks like

<constant>PIX_FMT_XXX</constant>, defined in the <link

linkend="videodev">videodev.h</link> header file. These identifiers

<constant>PIX_FMT_XXX</constant>, defined in the <filename>videodev2.h</filename>

header file. These identifiers

represent <link linkend="v4l2-fourcc">four character codes</link>

which are also listed below, however they are not the same as those

used in the Windows world.</para>