mmc: sdhci: move timeout_clk dynamically calculation code into common code

The timeout_clk calculation code for SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK case
is common and could be moved into common sdhci_do_set_ios, then platform code
which is not using sdhci_set_clock does not need to write the same code again.

Signed-off-by: Dong Aisheng <b29396@freescale.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>