Fix no. of gpio cells in the pxa gpio binding doucmentation

Index: linux-4.7.1/Documentation/devicetree/bindings/gpio/mrvl-gpio.txt
===================================================================
@@ -17,7 +17,9 @@ Required properties:
 - #interrupt-cells: Specifies the number of cells needed to encode an
   interrupt source.
 - gpio-controller : Marks the device node as a gpio controller.
-- #gpio-cells : Should be one.  It is the pin number.
+- #gpio-cells : Should be two.  The first cell is the pin number and
+  the second cell is used to specify flags. See gpio.txt for possible
+  values.
 
 Example for a MMP platform:
 

@@ -27,7 +29,7 @@ Example for a MMP platform:
 		interrupts = <49>;
 		interrupt-names = "gpio_mux";
 		gpio-controller;
-		#gpio-cells = <1>;
+		#gpio-cells = <2>;
 		interrupt-controller;
 		#interrupt-cells = <1>;
       };