Set correct UHS Mode Select field value for UHS SDR25 (50MHz) mode.
Fixes: d1c0a2200afb ("mmc: sdhci: Add support for HOST_CONTROL2 and setting UHS timings") Signed-off-by: Jonas Karlman <jonas@kwiboo.se> Reviewed-by: Kever Yang <kever.yang@rock-chips.com>