ARM: dts: imx53-ppd: Use #pwm-cells = <3> for imx27-pwm device

The binding dictates using 3 pwm-cells. Adhere to that.

This fixes the following dtbs_check warnings:

	arch/arm/boot/dts/nxp/imx/imx53-ppd.dtb: pwm@53fb4000: #pwm-cells:0:0: 3 was expected
		from schema : http://devicetree.org/schemas/pwm/imx-pwm.yaml#
	arch/arm/boot/dts/nxp/imx/imx53-ppd.dtb: pwm@53fb8000: #pwm-cells:0:0: 3 was expected
		from schema : http://devicetree.org/schemas/pwm/imx-pwm.yaml#Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/nxp/imx/imx53-ppd.dts

@@ -167,7 +167,7 @@ reg_3v3_lcd: regulator-3v3-lcd {
 
 	pwm_bl: backlight {
 		compatible = "pwm-backlight";
-		pwms = <&pwm2 0 50000>;
+		pwms = <&pwm2 0 50000 0>;
 		brightness-levels = <0 2 5 7 10 12 15 17 20 22 25 28 30 33 35
 				     38 40 43 45 48 51 53 56 58 61 63 66 68 71
 				     73 76 79 81 84 86 89 91 94 96 99 102 104
@@ -187,7 +187,7 @@ led-controller-1 {
 
 		led-1 {
 			label = "alarm-brightness";
-			pwms = <&pwm1 0 100000>;
+			pwms = <&pwm1 0 100000 0>;
 			max-brightness = <255>;
 		};
 	};
@@ -628,14 +628,12 @@ &pmu {
 };
 
 &pwm1 {
-	#pwm-cells = <2>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_pwm1>;
 	status = "okay";
 };
 
 &pwm2 {
-	#pwm-cells = <2>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_pwm2>;
 	status = "okay";