mmc: sdhci: Refactor sdhci_set_timeout()

Refactor sdhci_set_timeout() such that platform drivers can do some
functionality in a set_timeout() callback and then call
__sdhci_set_timeout() to complete the operation.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20200116105154.7685-7-faiz_abbas@ti.com


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