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>