arm64: dts: imx8mm-phyboard-polis: Add i2c4 sda-/scl-gpios

Add i2c4 sda-/scl-gpios with the corresponding pinmux entries.
Signed-off-by: Cem Tenruh <c.tenruh@phytec.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mm-phyboard-polis-rdk.dts

@@ -191,8 +191,11 @@ &gpio5 {
 
 &i2c4 {
 	clock-frequency = <400000>;
-	pinctrl-names = "default";
+	pinctrl-names = "default", "gpio";
 	pinctrl-0 = <&pinctrl_i2c4>;
+	pinctrl-1 = <&pinctrl_i2c4_gpio>;
+	sda-gpios = <&gpio5 21 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+	scl-gpios = <&gpio5 20 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
 };
 
 /* PCIe */
@@ -376,6 +379,13 @@ MX8MM_IOMUXC_I2C4_SDA_I2C4_SDA		0x400001c2
 		>;
 	};
 
+	pinctrl_i2c4_gpio: i2c4gpiogrp {
+		fsl,pins = <
+			MX8MM_IOMUXC_I2C4_SCL_GPIO5_IO20        0x1e2
+			MX8MM_IOMUXC_I2C4_SDA_GPIO5_IO21        0x1e2
+		>;
+	};
+
 	pinctrl_leds: leds1grp {
 		fsl,pins = <
 			MX8MM_IOMUXC_GPIO1_IO01_GPIO1_IO1	0x16