arm64: dts: imx8mm-evk: Add flexspi support

imx8mm-evk has a quad SPI-NOR flash on the flexspi bus.

Add support for it.
Signed-off-by: NFabio Estevam <festevam@gmail.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mm-evk.dts

@@ -12,6 +12,10 @@
 	model = "FSL i.MX8MM EVK board";
 	compatible = "fsl,imx8mm-evk", "fsl,imx8mm";
 
+	aliases {
+		spi0 = &flexspi;
+	};
+
 	chosen {
 		stdout-path = &uart2;
 	};
@@ -135,6 +139,22 @@
 	};
 };
 
+&flexspi {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_flexspi>;
+	status = "okay";
+
+	flash@0 {
+		reg = <0>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "jedec,spi-nor";
+		spi-max-frequency = <80000000>;
+		spi-tx-bus-width = <4>;
+		spi-rx-bus-width = <4>;
+	};
+};
+
 &i2c1 {
 	clock-frequency = <400000>;
 	pinctrl-names = "default";
@@ -423,6 +443,17 @@
 		>;
 	};
 
+	pinctrl_flexspi: flexspigrp {
+		fsl,pins = <
+			MX8MM_IOMUXC_NAND_ALE_QSPI_A_SCLK               0x1c2
+			MX8MM_IOMUXC_NAND_CE0_B_QSPI_A_SS0_B            0x82
+			MX8MM_IOMUXC_NAND_DATA00_QSPI_A_DATA0           0x82
+			MX8MM_IOMUXC_NAND_DATA01_QSPI_A_DATA1           0x82
+			MX8MM_IOMUXC_NAND_DATA02_QSPI_A_DATA2           0x82
+			MX8MM_IOMUXC_NAND_DATA03_QSPI_A_DATA3           0x82
+		>;
+	};
+
 	pinctrl_pmic: pmicirq {
 		fsl,pins = <
 			MX8MM_IOMUXC_GPIO1_IO03_GPIO1_IO3		0x41