docs: uapi: media: ignore new DVB-S2X FEC values

Some new FEC values was added to support DVB-S2X. They're properly
documented, but its addition adds some extra warnings to htmldocs
build. So, add them to the ignore list.

Fixes: 1825788e2a96 ("media: dvb: add missing DVB-S2X FEC parameter values")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: media/frontend.h.rst.exceptions: add exceptions for new dvb defines

After some dvb/frontend.h additions, building the documentation
gives lots of warnings. Add the missing pieces to
frontend.h.rst.exceptions.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@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>