docs: Add more manuals to the PDF build

There were a few manuals that weren't being built in PDF format, but
there's no reason not to...

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/security/conf.py b/Documentation/security/conf.py
new file mode 100644
index 0000000..472fc9a
--- /dev/null
+++ b/Documentation/security/conf.py
@@ -0,0 +1,8 @@
+project = "The kernel security subsystem manual"
+
+tags.add("subproject")
+
+latex_documents = [
+    ('index', 'security.tex', project,
+     'The kernel development community', 'manual'),
+]