gpio: mrvl: documentation: trivial: fix typo

fix typo in the document.
Signed-off-by: NJosh Wu <josh.wu@atmel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/gpio/mrvl-gpio.txt

@@ -12,7 +12,7 @@ Required properties:
   gpio_mux.
 - interrupt-names : Should be the names of irq resources. Each interrupt
   uses its own interrupt name, so there should be as many interrupt names
-  as referenced interrups.
+  as referenced interrupts.
 - interrupt-controller : Identifies the node as an interrupt controller.
 - #interrupt-cells: Specifies the number of cells needed to encode an
   interrupt source.