mmc: sdhci: revert "mmc: sdhci: Claer high speed if not supported"

mmc: sdhci: revert "mmc: sdhci: Claer high speed if not supported"

This "commit 429790026021d522d51617217d4b86218cca5750" is wrong.
SDHCI_QUIRK_NO_HISPD_BIT is for skipping to set CTRL_HISPD bit.

For example, Exynos didn't have CTRL_HISPD. But Highspeed mode
is supported.
(This quirks doesn't mean  that driver didn't support the Highseepd mode.)

Note: If driver didn't support the Highspeed Mode, use or add the other
quirks.

After applied this patch, all Exynos SoCs are just running with 25MHz.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>