sdhci-s3c: add SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK quirk

On Samsung's SDMMC hosts the timeout clock is derivied from the SD Clock
which is set dynamically.  So checked SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK
quirk and removed 'sdhci_s3c_get_timeout_clk' callback which doesn't need
any more.

Signed-off-by: Hyuk Lee <hyuk1.lee@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>