ARM: dts: imx6sl: add initial imx6sl-evk support

Add initial imx6sl-evk board support with uart, usdhc and fec enabled.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index f56e599..80a4603 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -121,7 +121,8 @@
 	imx6q-sabreauto.dtb \
 	imx6q-sabrelite.dtb \
 	imx6q-sabresd.dtb \
-	imx6q-sbc6x.dtb
+	imx6q-sbc6x.dtb \
+	imx6sl-evk.dtb
 dtb-$(CONFIG_ARCH_MXS) += imx23-evk.dtb \
 	imx23-olinuxino.dtb \
 	imx23-stmp378x_devb.dtb \