arm64: dts: imx8ulp: add #reset-cells for pcc

The binding file clock/imx8ulp-pcc-clock.yaml indicates '#reset-cells'
is a required property, add it.

Fixes: fe6291e9 ("arm64: dts: imx8ulp: Add the basic dtsi file for imx8ulp")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8ulp.dtsi

@@ -172,6 +172,7 @@ pcc3: clock-controller@292d0000 {
 				compatible = "fsl,imx8ulp-pcc3";
 				reg = <0x292d0000 0x10000>;
 				#clock-cells = <1>;
+				#reset-cells = <1>;
 			};
 
 			tpm5: tpm@29340000 {
@@ -270,6 +271,7 @@ pcc4: clock-controller@29800000 {
 				compatible = "fsl,imx8ulp-pcc4";
 				reg = <0x29800000 0x10000>;
 				#clock-cells = <1>;
+				#reset-cells = <1>;
 			};
 
 			lpi2c6: i2c@29840000 {
@@ -414,6 +416,7 @@ pcc5: clock-controller@2da70000 {
 				compatible = "fsl,imx8ulp-pcc5";
 				reg = <0x2da70000 0x10000>;
 				#clock-cells = <1>;
+				#reset-cells = <1>;
 			};
 		};