It's possible that the controller has an individually switchable power supply.
Therefore add support to control a supplying regulator.

As this is not always the case, the regulator is requested as optional.
Signed-off-by: NHeiko Stuebner <heiko.stuebner@bq.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

This makes the zforce driver usable on devicetree-based platforms too.
Signed-off-by: NHeiko Stuebner <heiko.stuebner@bqreaders.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Add the necessary code to create the needed platformdata from devicetree
informations.

The interrupt mode of the chip is not set via devicetree, as it is not
a property of the hardware but instead only a preferred type of operation.
This should probably be made settable via configfs in the future.
The option set as default is the mode the datasheet mentions as default.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>