media: intro.rst: don't assume audio and video codecs to be MPEG2

Originally, when DVB was introduced, all codecs would be part of
MPEG2 standard. That's not true anymore, as there are a large
number of codec standards used on digital TV nowadays.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/media/uapi/dvb/intro.rst

@@ -94,11 +94,10 @@ Demultiplexer which filters the incoming Digital TV MPEG-TS stream
    streams it also contains data streams with information about the
    programs offered in this or other streams of the same provider.
 
-MPEG2 audio and video decoder
-   The main targets of the demultiplexer are the MPEG2 audio and video
-   decoders. After decoding they pass on the uncompressed audio and
-   video to the computer screen or (through a PAL/NTSC encoder) to a TV
-   set.
+Audio and video decoder
+   The main targets of the demultiplexer are audio and video
+   decoders. After decoding, they pass on the uncompressed audio and
+   video to the computer screen or to a TV set.
 
    .. note::