Some platforms (e.g. Picochip PC3XX) have multiple DMA controllers
where some may be used for slave transfers and others for general
purpose memcpy type transfers. Add a .is_private boolean to the
platform data structure so that controllers can be marked as private
so that the DMA_PRIVATE capability will be set for that controller.
Signed-off-by: NJamie Iles <jamie.iles@picochip.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>