ARM: dts: imx6qdl-savageboard: 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/imx6dl-savageboard.dtb: pwm@2080000: #pwm-cells:0:0: 3 was expected
		from schema : http://devicetree.org/schemas/pwm/imx-pwm.yaml#
	arch/arm/boot/dts/nxp/imx/imx6q-savageboard.dtb: pwm@2080000: #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/imx6qdl-savageboard.dtsi

@@ -83,7 +83,7 @@ panel_bl: backlight {
 		brightness-levels = <0 4 8 16 32 64 128 255>;
 		default-brightness-level = <4>;
 		power-supply = <&reg_3p3v>;
-		pwms = <&pwm1 0 10000>;
+		pwms = <&pwm1 0 10000 0>;
 	};
 
 	reg_3p3v: regulator-3p3v {
@@ -140,7 +140,6 @@ lvds0_out: endpoint {
 };
 
 &pwm1 {
-	#pwm-cells = <2>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_pwm1>;
 	status = "okay";