mmc: sdhci-pci-gli: A workaround to allow GL9750 to enter ASPM L1.2

When GL9750 enters ASPM L1 sub-states, it will stay at L1.1 and will not
enter L1.2. The workaround is to toggle PM state to allow GL9750 to enter
ASPM L1.2.

Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
Link: https://lore.kernel.org/r/20230912091710.7797-1-victorshihgli@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>