STMPE gpio
----------

Required properties:
 - compatible: "st,stmpe-gpio"

Optional properties:
 - st,norequest-mask: bitmask specifying which GPIOs should _not_ be requestable
   due to different usage (e.g. touch, keypad)

Node should be child node of stmpe node to which it belongs.

Example:
	stmpe_gpio {
		compatible = "st,stmpe-gpio";
		st,norequest-mask = <0x20>;	//gpio 5 can't be used
	};