Document the previously introduced method that can be used by device
drivers to provide the GPIO subsystem with mappings between GPIO names
(connection IDs) and GpioIo()/GpioInt() resources in _CRS.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>