media: admin-guide: make clear about PCI subsystem IDs

On several parts of the document, it mentions "PCI ID", when
it is actually referring to the subsystem's part of the PCI
ID.

Change the language to let it be clear.

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

media: docs: update cardlists

There were some changes at the drivers adding support for
more cards. Update cardlists accordingly.

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

media: docs: move user-facing docs to the admin guide

Most of the driver-specific documentation is meant to help
users of the media subsystem.

Move them to the admin-guide.

It should be noticed, however, that several of those files
are outdated and will require further work in order to make
them useful again.

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