TODO

 1This is a list of things that need to be done to get this driver out of the
 2staging directory.
 3
 4- Request API conversion. Remove of the dual pipeline and associate buffers
 5  as well as formats and the binary used to a request. Remove the
 6  opportunistic buffer management. (Sakari)
 7
 8- IPU3 driver documentation (Laurent)
 9  Comments on configuring v4l2 subdevs for CIO2 and ImgU.
10
11- Elaborate the functionality of different selection rectangles in driver
12  documentation. This may require driver changes as well.