staging/atomisp: Add support for the Intel IPU v2

This patch adds support for the Intel IPU v2 as found on Android and IoT
Baytrail-T and Baytrail-CR platforms (those with the IPU PCI mapped). You
will also need the firmware files from your device (Android usually puts
them into /etc) - or you can find them in the downloadable restore/upgrade
kits if you blew them away for some reason.

It may be possible to extend the driver to handle the BYT/T windows
platforms such as the ASUS T100TA. These platforms don't expose the IPU via
the PCI interface but via ACPI buried in the GPU description and with the
camera information somewhere unknown so would need a platform driver
interface adding to the codebase *IFF* the firmware works on such devices.

To get good results you also need a suitable support library such as
libxcam. The camera is intended to be driven from Android so it has a lot of
features that many desktop apps don't fully spport.

In theory all the pieces are there to build it with -DISP2401 and some
differing files to get CherryTrail/T support, but unifying the drivers
properlly is a work in progress.

The IPU driver represents the work of a lot of people within Intel over many
years. It's historical goal was portability rather than Linux upstream. Any
queries about the upstream aimed driver should be sent to me not to the
original authors.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>