Add needed platform data structure and code to be able to load
the GPO child of twl6040.
Update the devicetree binding documentation at the same time.
Signed-off-by: NSergio Aguirre <saaguirre@ti.com>
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>