imx8mn_var_som: Add support for Variscite VAR-SOM-MX8M-NANO board

Add support for iMX8MN VAR-SOM-MX8M-NANO board. Enables support for:

- 1GiB DDR4 RAM
- 16 GiB eMMC
- SD card
- Gigabit ethernet
- USBOTG1 peripheral - fastboot

Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@collabora.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/board/variscite/imx8mn_var_som/imximage-8mn-ddr4.cfg b/board/variscite/imx8mn_var_som/imximage-8mn-ddr4.cfg
new file mode 100644
index 0000000..2083233
--- /dev/null
+++ b/board/variscite/imx8mn_var_som/imximage-8mn-ddr4.cfg
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2021 Collabora Ltd.
+ */
+
+#define __ASSEMBLY__
+
+ROM_VERSION	v2
+BOOT_FROM	sd
+LOADER		u-boot-spl-ddr.bin	0x912000