arm64: dts: socfpga: agilex: align pin-controller name with bindings

Use a generic node name for the pin controller node to fix:

  /socfpga_agilex_n6000.dtb: pinconf@ffd13100: $nodename:0: 'pinconf@ffd13100' does not match '^(pinctrl|pinmux)(@[0-9a-f]+)?$'
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

arch/arm64/boot/dts/intel/socfpga_agilex.dtsi

@@ -368,7 +368,7 @@ pinctrl0: pinctrl@ffd13000 {
 			pinctrl-single,function-mask = <0x0000000f>;
 		};
 
-		pinctrl1: pinconf@ffd13100 {
+		pinctrl1: pinctrl@ffd13100 {
 			compatible = "pinctrl-single";
 			#pinctrl-cells = <1>;
 			reg = <0xffd13100 0x20>;