ARM: dts: imx6sl-warp: Pass 'bus-width' property

USDHC2 port uses all the 8 data signals, so pass the 'bus-width' property
accordingly.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Acked-by: NOtavio Salvador <otavio@ossystems.com.br>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

arch/arm/boot/dts/imx6sl-warp.dts

@@ -122,6 +122,7 @@
 	pinctrl-0 = <&pinctrl_usdhc2>;
 	pinctrl-1 = <&pinctrl_usdhc2_100mhz>;
 	pinctrl-2 = <&pinctrl_usdhc2_200mhz>;
+	bus-width = <8>;
 	non-removable;
 	status = "okay";
 };