Revert "mmc: sdhci: Fix incorrect switch to HS mode"

This reverts commit c894e33d

.

This commit aims to treat SD High speed and SDR25 as the same while
setting UHS Timings in HOST_CONTROL2 which leads to failures with some
SD cards in AM65x. Revert this commit.

The issue this commit was trying to fix can be implemented in a platform
specific callback instead of common sdhci code.

Cc: <stable@vger.kernel.org>
Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20191128110422.25917-1-faiz_abbas@ti.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>