mmc: sdhci: Remove unused prototype declaration in the header

sdhci_card_detect() is not defined anywhere. Remove it.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20211014132613.27861-3-andriy.shevchenko@linux.intel.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci.h

@@ -750,7 +750,6 @@ static inline void *sdhci_priv(struct sdhci_host *host)
 	return host->private;
 }
 
-void sdhci_card_detect(struct sdhci_host *host);
 void __sdhci_read_caps(struct sdhci_host *host, const u16 *ver,
 		       const u32 *caps, const u32 *caps1);
 int sdhci_setup_host(struct sdhci_host *host);