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 <[e-mail]>
Reviewed-by: Javier Martinez Canillas <[e-mail]>
Acked-by: Mark Rutland <[e-mail]>
Signed-off-by: Benoit Cousson <[e-mail]>

arch/arm/boot/dts/am33xx.dtsi

···
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 			reg = <0x44e07000 0x1000>;
 			interrupts = <96>;
 		};
···
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 			reg = <0x4804c000 0x1000>;
 			interrupts = <98>;
 		};
···
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 			reg = <0x481ac000 0x1000>;
 			interrupts = <32>;
 		};
···
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 			reg = <0x481ae000 0x1000>;
 			interrupts = <62>;
 		};