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/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index cd24d7e..a98dfc4 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -914,6 +914,7 @@
 	imx8mn-ddr4-evk.dtb \
 	imx8mq-cm.dtb \
 	imx8mn-evk.dtb \
+	imx8mn-var-som-symphony.dtb \
 	imx8mq-evk.dtb \
 	imx8mm-beacon-kit.dtb \
 	imx8mn-beacon-kit.dtb \