mmc: dw_mmc: remove the 'id' arguments about functions relevant to slot

Doesn't need to pass the id value for slot functions.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>