ARM: dts: imx: add Boundary Devices Nitrogen7 board

Based on i.MX7 Dual with 1GB of RAM.

https://boundarydevices.com/product/nitrogen7/

Signed-off-by: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index 95c1923..65e99f8 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -377,6 +377,7 @@
 	imx6ul-14x14-evk.dtb
 dtb-$(CONFIG_SOC_IMX7D) += \
 	imx7d-cl-som-imx7.dtb \
+	imx7d-nitrogen7.dtb \
 	imx7d-sbc-imx7.dtb \
 	imx7d-sdb.dtb
 dtb-$(CONFIG_SOC_LS1021A) += \