Documentation: exclude media documentation from pdf generation

Although pdflatex is more robust than rst2pdf, building media
documentation pdf still fails. Exclude media documentation from pdf
generation for now.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Markus Heiser <markus.heiser@darmarit.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/conf.py

@@ -268,7 +268,9 @@
 # (source start file, target name, title,
 #  author, documentclass [howto, manual, or own class]).
 latex_documents = [
-    (master_doc, 'TheLinuxKernel.tex', 'The Linux Kernel Documentation',
+    ('kernel-documentation', 'kernel-documentation.tex', 'The Linux Kernel Documentation',
+     'The kernel development community', 'manual'),
+    ('gpu/index', 'gpu.tex', 'Linux GPU Driver Developer\'s Guide',
      'The kernel development community', 'manual'),
 ]