mmc: sdhci-pci-o2micro: Fix card detect by dealing with debouncing

The result from ->get_cd() may be incorrect as the card detect debouncing
isn't managed correctly. Let's fix it.

Signed-off-by: Chevron <Li&lt;chevron.li@bayhubtech.com>
Fixes: 7d440617

 ("mmc: sdhci-pci-o2micro: Fix O2 Host data read/write DLL Lock phase shift issue")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220602132543.596-1-chevron.li@bayhubtech.com
[Ulf: Updated the commit message]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>