media: xilinx: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style
in header files related to Video drivers for Xilinx devices.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used)

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: xilinx: Use SPDX-License-Identifier

SPDX-License-Identifier is used for the Xilinx Video IP and
related drivers.

[Added drivers/media/platform/xilinx/Kconfig]
[Added drivers/media/platform/xilinx/Makefile]
[Added include/dt-bindings/media/xilinx-vip.h]

Signed-off-by: Dhaval Shah <dhaval23031987@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: platform: Switch to v4l2_async_notifier_add_subdev

Switch all media platform drivers to call v4l2_async_notifier_add_subdev()
to add asd's to a notifier, in place of referencing the notifier->subdevs[]
array. These drivers also must now call v4l2_async_notifier_init() before
adding asd's to their notifiers.

There may still be cases where a platform driver maintains a list of
asd's that is a duplicate of the notifier asd_list, in which case its
possible the platform driver list can be removed, and can reference the
notifier asd_list instead. One example of where a duplicate list has
been removed in this patch is xilinx-vipp.c. If there are such cases
remaining, those drivers should be optimized to remove the duplicate
platform driver asd lists.

None of the changes to the platform drivers in this patch have been
tested. Verify that the async subdevices needed by the platform are
bound at load time, and that the driver unloads and reloads correctly
with no memory leaking of asd objects.

Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

[media] v4l: xilinx: Add Xilinx Video IP core

Xilinx platforms have no hardwired video capture or video processing
interface. Users create capture and memory to memory processing
pipelines in the FPGA fabric to suit their particular needs, by
instantiating video IP cores from a large library.

The Xilinx Video IP core is a framework that models a video pipeline
described in the device tree and expose the pipeline to userspace
through the media controller and V4L2 APIs.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hyun Kwon <hyun.kwon@xilinx.com>
Signed-off-by: Radhey Shyam Pandey <radheys@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>