media: docs: move driver-specific info to driver-api

Those documents don't really describe the driver API.

Instead, they contain development-specific information.

Yet, as the main index file describes the content of it as:

"how specific kernel subsystems work
from the point of view of a kernel developer"

It seems to be the better fit.

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

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 135 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081036.435762997@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

media: dvb: point to the location of the old README.dvb-usb file

This file got renamed, but the references still point to the
old place.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>

[media] move the dvb/frontends to drivers/media/dvb-frontends

Raise the DVB frontends one level up, as the intention is to remove
the drivers/media/dvb directory.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>