doc-rst: dvb/intro: Better show the needed include blocks

The include blocks were not properly displayed. Fix it.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/linux_tv/media/dvb/intro.rst

@@ -160,34 +160,16 @@ partial path like:
 
 	#include <linux/dvb/audio.h>
 
-
-.. code-block:: c
-
 	#include <linux/dvb/ca.h>
 
-
-.. code-block:: c
-
 	#include <linux/dvb/dmx.h>
 
-
-.. code-block:: c
-
 	#include <linux/dvb/frontend.h>
 
-
-.. code-block:: c
-
 	#include <linux/dvb/net.h>
 
-
-.. code-block:: c
-
 	#include <linux/dvb/osd.h>
 
-
-.. code-block:: c
-
 	#include <linux/dvb/video.h>
 
 To enable applications to support different API version, an additional