doc: add texinfodocs and infodocs targets

Sphinx supports generating Texinfo sources and Info documentation,
which can be navigated easily and is convenient to search (via the
indexed nodes or anchors, for example).

Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>
Link: https://lore.kernel.org/r/20221116190210.28407-2-maxim.cournoyer@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

media: docs: move DVB audio/video docs to staging

The only upstream driver using the API described there is the
av7110 driver.

As the driver was moved to staging, move the API bits to staging
as well.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: docs: move uAPI book to userspace-api/media

Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee3862 ("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>