renesas_usbhs DMAEngine uses D0FIFO/D1FIFO,
but the data transfer direction should be fixed for keeping consistency.
This patch explain about it on renesas_usbhs.h
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>