ARM: dts: AM33xx: Correct gpio #interrupt-cells property

Following commit ff5c9059 and therefore other omap platforms using
the gpio-omap driver correct the #interrupt-cells property on am33xx
too. The omap gpio binding documentaion also states that
the #interrupt-cells property should be 2.
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Reviewed-by: Javier Martinez Canillas <javier@dowhile0.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Benoit Cousson <bcousson@baylibre.com>

arch/arm/boot/dts/am33xx.dtsi

@@ -111,7 +111,7 @@ gpio0: gpio@44e07000 {
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 			reg = <0x44e07000 0x1000>;
 			interrupts = <96>;
 		};
@@ -122,7 +122,7 @@ gpio1: gpio@4804c000 {
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 			reg = <0x4804c000 0x1000>;
 			interrupts = <98>;
 		};
@@ -133,7 +133,7 @@ gpio2: gpio@481ac000 {
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 			reg = <0x481ac000 0x1000>;
 			interrupts = <32>;
 		};
@@ -144,7 +144,7 @@ gpio3: gpio@481ae000 {
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 			reg = <0x481ae000 0x1000>;
 			interrupts = <62>;
 		};