V4L/DVB (13476): spec: remove old dvb-spec and v4l2-spec directories

It was really confusing to have media-specs, v4l2-spec and dvb-spec.
So this patch removes v4l2-spec and dvb-spec. The docs in dvb-spec and
the V4L1_API.html file were moved to media-specs/old-docs.

Removed all references to v4l2-spec and dvb-spec.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Documentation/video4linux/si4713.txt

@@ -164,7 +164,7 @@ Stereo/Mono and RDS subchannels
 
 The device can also be configured using the available sub channels for
 transmission. To do that use S/G_MODULATOR ioctl and configure txsubchans properly.
-Refer to v4l2-spec for proper use of this ioctl.
+Refer to the V4L2 API specification for proper use of this ioctl.
 
 Testing
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