docs: media: dvb: use TOC instead of file contents at headers

All we wanted were to have a way to link the comprehensive
documentation with the actual symbols parsed from the header
file, as this helps to identify any broken references.

Use the new :toc: flag for DVB.

Signed-off-by: Mauro Carvalho Chehab <[e-mail]>
Signed-off-by: Jonathan Corbet <[e-mail]>
Message-ID: <dbe95d[e-mail]>

Documentation/userspace-api/media/dvb/headers.rst

···
 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
 
-****************************
-Digital TV uAPI header files
-****************************
-
-Digital TV uAPI headers
 ***********************
+Digital TV uAPI symbols
+***********************
+
+.. contents:: Table of Contents
+   :depth: 2
+   :local:
+
+Frontend
+========
 
 .. kernel-include:: include/uapi/linux/dvb/frontend.h
     :generate-cross-refs:
     :exception-file: frontend.h.rst.exceptions
+    :toc:
+
+Demux
+=====
 
 .. kernel-include:: include/uapi/linux/dvb/dmx.h
     :generate-cross-refs:
     :exception-file: dmx.h.rst.exceptions
+    :toc:
+
+Conditional Access
+==================
 
 .. kernel-include:: include/uapi/linux/dvb/ca.h
     :generate-cross-refs:
     :exception-file: ca.h.rst.exceptions
+    :toc:
+
+Network
+=======
 
 .. kernel-include:: include/uapi/linux/dvb/net.h
     :generate-cross-refs:
     :exception-file: net.h.rst.exceptions
+    :toc: