docs-rst: add media documentation to PDF output

Now that the build of PDF output on media got fixed, re-add it
to the Sphinx PDF build.

Partially reverts 3eb6cd68 ('Documentation: exclude
media documentation from pdf generation').
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/conf.py

@@ -340,6 +340,8 @@ latex_documents = [
      'The kernel development community', 'manual'),
     ('gpu/index', 'gpu.tex', 'Linux GPU Driver Developer\'s Guide',
      'The kernel development community', 'manual'),
+    ('media/index', 'media.tex', 'Linux Media Subsystem Documentation',
+     'The kernel development community', 'manual'),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of