imx: add i.MX8MN DDR4 board support

Support pinctrl/clk/sdhc, include ddr4 timing data.

Log:
U-Boot SPL 2019.10-rc3-00356-g497c500423-dirty (Sep 16 2019 - 10:54:58 +0800)
Normal Boot
Trying to boot from BOOTROM
image offset 0x8000, pagesize 0x200, ivt offset 0x0

U-Boot 2019.10-rc3-00356-g497c500423-dirty (Sep 16 2019 - 10:54:58 +0800)

CPU:   Freescale i.MX8MNano rev1.0 at 24 MHz
Reset cause: POR
Model: NXP i.MX8MNano DDR4 EVK board
DRAM:  2 GiB
MMC:   FSL_SDHC: 1, FSL_SDHC: 2
Loading Environment from MMC... *** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   No ethernet found.
Hit any key to stop autoboot:  0

Signed-off-by: Peng Fan <peng.fan@nxp.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/board/freescale/imx8mn_evk/imx8mn_evk.c b/board/freescale/imx8mn_evk/imx8mn_evk.c
new file mode 100644
index 0000000000..b22a2a6bd1
--- /dev/null
+++ b/board/freescale/imx8mn_evk/imx8mn_evk.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2019 NXP
+ */
+
+#include <common.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int dram_init(void)
+{
+	gd->ram_size = PHYS_SDRAM_SIZE;
+
+	return 0;
+}
+
+int board_init(void)
+{
+	return 0;
+}
+
+int board_late_init(void)
+{
+#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
+	env_set("board_name", "DDR4 EVK");
+	env_set("board_rev", "iMX8MN");
+#endif
+	return 0;
+}