Document the use of references into the hierarchical data extension
structure, as well as the use of port and endpoint concepts that are very
similar to those in Devicetree.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
