mmc: sdhci-pci-o2micro: Fix SDR50 mode timing issue

Change SDR50 mode clock source from DLL output clock to PLL open clock
1.HS200 and SDR104 mode select DLL output clock
2.SDR50 mode select PLL open clock

Signed-off-by: Fred <fred.ai@bayhubtech.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20230223120450.16858-1-fredaibayhubtech@126.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>