imx: mx6sx: add dts for mx6sxsabreauto board

Add dts for mx6sxsabreauto board.
dts related files imported fro Linux (commit e5517c2a5a4).

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index 6a7924e..01aac13 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -313,6 +313,7 @@
 	imx6dl-icore-rqs.dtb \
 	imx6q-icore.dtb \
 	imx6q-icore-rqs.dtb \
+	imx6sx-sabreauto.dtb \
 	imx6ul-geam-kit.dtb
 
 dtb-$(CONFIG_MX7) += imx7-colibri.dtb