ARM: dts: imx7s: fix iomuxc_lpsr node name

Schema requires the node being named 'pinctrl'.
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx7s.dtsi

@@ -446,7 +446,7 @@ wdog4: watchdog@302b0000 {
 				status = "disabled";
 			};
 
-			iomuxc_lpsr: iomuxc-lpsr@302c0000 {
+			iomuxc_lpsr: pinctrl@302c0000 {
 				compatible = "fsl,imx7d-iomuxc-lpsr";
 				reg = <0x302c0000 0x10000>;
 				fsl,input-sel = <&iomuxc>;