Add DocBook documentation for the new multi-planar API extensions to the
Video for Linux 2 API DocBook.
Signed-off-by: NPawel Osciak <pawel@osciak.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The V4L and DVB API's are there for a long time. however, up to now,
no efforts were done to merge them to kernel DocBook.

This patch adds the current versions of the specs as an unique compendium.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>