mmc: dw_mmc: enable card read threshold when mode is HS400

Enable card-read-threshold, when eMMC mode is HS400.
Refer to f1d2736c8156 (mmc: dw_mmc: control card read threshold)

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
1 file changed