nitrogen6x: migrate to using device tree

Migrate to using device tree required for further driver model
integration.

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
diff --git a/board/boundary/nitrogen6x/MAINTAINERS b/board/boundary/nitrogen6x/MAINTAINERS
index 1602d65..17018d6 100644
--- a/board/boundary/nitrogen6x/MAINTAINERS
+++ b/board/boundary/nitrogen6x/MAINTAINERS
@@ -1,6 +1,11 @@
 NITROGEN6X BOARD
 M:	Troy Kisky <troy.kisky@boundarydevices.com>
 S:	Maintained
+F:	arch/arm/dts/imx6dl-nitrogen6x.dts
+F:	arch/arm/dts/imx6q-nitrogen6x.dts
+F:	arch/arm/dts/imx6q-sabrelite.dts
+F:	arch/arm/dts/imx6qdl-nitrogen6x.dtsi
+F:	arch/arm/dts/imx6qdl-sabrelite.dtsi
 F:	board/boundary/nitrogen6x/
 F:	include/configs/nitrogen6x.h
 F:	configs/mx6qsabrelite_defconfig