arm64: dts: imx8mn-evk: update i2c pinctrl to match dtschema

The dtschema requires 'grp' in the end, so update the name.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi

@@ -389,7 +389,7 @@ MX8MN_IOMUXC_I2C2_SDA_I2C2_SDA		0x400001c3
 		>;
 	};
 
-	pinctrl_i2c2_gpio: i2c2grp-gpio {
+	pinctrl_i2c2_gpio: i2c2gpiogrp {
 		fsl,pins = <
 			MX8MN_IOMUXC_I2C2_SCL_GPIO5_IO16	0x1c3
 			MX8MN_IOMUXC_I2C2_SDA_GPIO5_IO17	0x1c3
@@ -403,7 +403,7 @@ MX8MN_IOMUXC_I2C3_SDA_I2C3_SDA		0x400001c3
 		>;
 	};
 
-	pinctrl_i2c3_gpio: i2c3grp-gpio {
+	pinctrl_i2c3_gpio: i2c3gpiogrp {
 		fsl,pins = <
 			MX8MN_IOMUXC_I2C3_SCL_GPIO5_IO18	0x1c3
 			MX8MN_IOMUXC_I2C3_SDA_GPIO5_IO19	0x1c3