I2SE's duckbills are only equipped with a micro SD card slot and
thus only provide a 4-bit interface.
Signed-off-by: NMichael Heimpold <mhei@heimpold.de>
Acked-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NShawn Guo <shawn.guo@freescale.com>