rockchip: mmc: get the fifo mode and fifo depth property from dts

rockchip: mmc: get the fifo mode and fifo depth property from dts

rk3036 mmc do not have internal dma, so we use fifo mode when read
and write data, we get the fifo mode and fifo depth property from
dts, pass to dw_mmc driver.

Signed-off-by: Lin Huang <hl@rock-chips.com>