arm64: dts: ti: k3-am642-evm: Add GPIO expander node

Add pinmux details and device tree node for GPIO expander attached
to I2C1 in main domain.

Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>

arch/arm64/boot/dts/ti/k3-am642-evm.dts

@@ -91,6 +91,13 @@ main_usb0_pins_default: main-usb0-pins-default {
 			AM64X_IOPAD(0x02a8, PIN_OUTPUT, 0) /* (E19) USB0_DRVVBUS */
 		>;
 	};
+
+	main_i2c1_pins_default: main-i2c1-pins-default {
+		pinctrl-single,pins = <
+			AM64X_IOPAD(0x0268, PIN_INPUT_PULLUP, 0) /* (C18) I2C1_SCL */
+			AM64X_IOPAD(0x026c, PIN_INPUT_PULLUP, 0) /* (B19) I2C1_SDA */
+		>;
+	};
 };
 
 &cpsw3g {
@@ -127,3 +134,16 @@ &usb0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&main_usb0_pins_default>;
 };
+
+&main_i2c1 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&main_i2c1_pins_default>;
+	clock-frequency = <400000>;
+
+	exp1: gpio@22 {
+		compatible = "ti,tca6424";
+		reg = <0x22>;
+		gpio-controller;
+		#gpio-cells = <2>;
+	};
+};