imx8mn: Add LPDDR4 EVK board support

Add support for iMX8MN LPDDR4 EVK board which uses 2GB LPDDR4 and
PCA9450B PMIC.

Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/dts/imx8mn-evk-u-boot.dtsi b/arch/arm/dts/imx8mn-evk-u-boot.dtsi
new file mode 100644
index 0000000..2730ff6
--- /dev/null
+++ b/arch/arm/dts/imx8mn-evk-u-boot.dtsi
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2019 NXP
+ */
+
+#include "imx8mn-ddr4-evk-u-boot.dtsi"
+
+&i2c1 {
+	u-boot,dm-spl;
+};
+
+&{/soc@0/bus@30800000/i2c@30a20000/pca9450@25} {
+	u-boot,dm-spl;
+};
+
+&{/soc@0/bus@30800000/i2c@30a20000/pca9450@25/regulators} {
+	u-boot,dm-spl;
+};
+
+&pinctrl_i2c1 {
+	u-boot,dm-spl;
+};
+
+&pinctrl_pmic {
+	u-boot,dm-spl;
+};