It makes more sense to place the xvideo example at the body,
keeping the footnote only to justify the design decision.
While this makes the text better, it also fixes the PDF
output.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee38 ("docs: Create a user-space API guide").
As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.
Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>