ARM: dts: imx: add initial imx6sx-sdb board support

Add initial imx6sx-sdb board support with limited devices enabled.

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index adb5ed9..cc776fc 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -216,6 +216,7 @@
 	imx6q-udoo.dtb \
 	imx6q-wandboard.dtb \
 	imx6sl-evk.dtb \
+	imx6sx-sdb.dtb \
 	vf610-colibri.dtb \
 	vf610-cosmic.dtb \
 	vf610-twr.dtb