mmc: dw_mmc-exynos: Add tuning for sdr and ddr timing for USH-I mode

Add tuning for sdr and ddr timing for USH-I mode sdr104/sdr50/ddr50
for host controller.

Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>