arm64: dts: imx8mp-evk: add PCA6416 interrupt controller mode

Add interrupt controller mode for the pca6416 on i.MX8MP EVK board's.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mp-evk.dts

@@ -294,6 +294,12 @@ pca6416: gpio@20 {
 		reg = <0x20>;
 		gpio-controller;
 		#gpio-cells = <2>;
+		interrupt-controller;
+		#interrupt-cells = <2>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_pca6416_int>;
+		interrupt-parent = <&gpio1>;
+		interrupts = <12 IRQ_TYPE_LEVEL_LOW>;
 	};
 };
 
@@ -448,6 +454,12 @@ MX8MP_IOMUXC_GPIO1_IO03__GPIO1_IO03	0x000001c0
 		>;
 	};
 
+	pinctrl_pca6416_int: pca6416_int_grp {
+		fsl,pins = <
+			MX8MP_IOMUXC_GPIO1_IO12__GPIO1_IO12	0x146 /* Input pull-up. */
+		>;
+	};
+
 	pinctrl_reg_usdhc2_vmmc: regusdhc2vmmcgrp {
 		fsl,pins = <
 			MX8MP_IOMUXC_SD2_RESET_B__GPIO2_IO19	0x41