Add HW tuning support for SD host controller in SDR104 mode

Signed-off-by: Shirley Her <shirley.her@bayhubtech.com>
Link: https://lore.kernel.org/r/20200721012700.8564-1-shirley.her@bayhubtech.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>