Portrait is too small for some tables used at the media docs.
So, allow documents to tell Sphinx to generate some pages
in landscape by using:

.. raw:: latex

    \begin{landscape}

<some stuff>

.. raw:: latex

    \end{landscape}
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>