Remove a section containing basically ideas for future sliced VBI standards.
This can be resurrected should any of this be actually implemented. For now
it only pollutes this header file.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>