arm64: dts: imx8mn-evk: Align pin configuration group names with schema

Device tree schema expects pin configuration groups to end with 'grp'
suffix, otherwise dtbs_check complain with a warning like:

    ... do not match any of the regexes: 'grp$', 'pinctrl-[0-9]+'
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

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

@@ -223,13 +223,13 @@ MX8MN_IOMUXC_I2C3_SDA_I2C3_SDA		0x400001c3
 		>;
 	};
 
-	pinctrl_pmic: pmicirq {
+	pinctrl_pmic: pmicirqgrp {
 		fsl,pins = <
 			MX8MN_IOMUXC_GPIO1_IO03_GPIO1_IO3	0x41
 		>;
 	};
 
-	pinctrl_reg_usdhc2_vmmc: regusdhc2vmmc {
+	pinctrl_reg_usdhc2_vmmc: regusdhc2vmmcgrp {
 		fsl,pins = <
 			MX8MN_IOMUXC_SD2_RESET_B_GPIO2_IO19	0x41
 		>;
@@ -248,7 +248,7 @@ MX8MN_IOMUXC_UART2_TXD_UART2_DCE_TX	0x140
 		>;
 	};
 
-	pinctrl_usdhc2_gpio: usdhc2grpgpio {
+	pinctrl_usdhc2_gpio: usdhc2gpiogrp {
 		fsl,pins = <
 			MX8MN_IOMUXC_GPIO1_IO15_GPIO1_IO15	0x1c4
 		>;
@@ -266,7 +266,7 @@ MX8MN_IOMUXC_GPIO1_IO04_USDHC2_VSELECT	0x1d0
 		>;
 	};
 
-	pinctrl_usdhc2_100mhz: usdhc2grp100mhz {
+	pinctrl_usdhc2_100mhz: usdhc2-100mhzgrp {
 		fsl,pins = <
 			MX8MN_IOMUXC_SD2_CLK_USDHC2_CLK		0x194
 			MX8MN_IOMUXC_SD2_CMD_USDHC2_CMD		0x1d4
@@ -278,7 +278,7 @@ MX8MN_IOMUXC_GPIO1_IO04_USDHC2_VSELECT	0x1d0
 		>;
 	};
 
-	pinctrl_usdhc2_200mhz: usdhc2grp200mhz {
+	pinctrl_usdhc2_200mhz: usdhc2-200mhzgrp {
 		fsl,pins = <
 			MX8MN_IOMUXC_SD2_CLK_USDHC2_CLK		0x196
 			MX8MN_IOMUXC_SD2_CMD_USDHC2_CMD		0x1d6
@@ -306,7 +306,7 @@ MX8MN_IOMUXC_NAND_CE1_B_USDHC3_STROBE		0x190
 		>;
 	};
 
-	pinctrl_usdhc3_100mhz: usdhc3grp100mhz {
+	pinctrl_usdhc3_100mhz: usdhc3-100mhzgrp {
 		fsl,pins = <
 			MX8MN_IOMUXC_NAND_WE_B_USDHC3_CLK		0x40000194
 			MX8MN_IOMUXC_NAND_WP_B_USDHC3_CMD		0x1d4
@@ -322,7 +322,7 @@ MX8MN_IOMUXC_NAND_CE1_B_USDHC3_STROBE		0x194
 		>;
 	};
 
-	pinctrl_usdhc3_200mhz: usdhc3grp200mhz {
+	pinctrl_usdhc3_200mhz: usdhc3-200mhzgrp {
 		fsl,pins = <
 			MX8MN_IOMUXC_NAND_WE_B_USDHC3_CLK		0x40000196
 			MX8MN_IOMUXC_NAND_WP_B_USDHC3_CMD		0x1d6