mmc: sdhci: drop useless sdhci_get_compatibility() !OF stub

The sdhci_get_compatibility() uses OF functions which have stubs for !OF
case, thus entire CONFIG_OF ifdef can be dropped.  This also fixes
!CONFIG_OF W=1 warning:

  drivers/mmc/host/sdhci-pltfm.c:76:6: error: no previous prototype for ‘sdhci_get_compatibility’ [-Werror=missing-prototypes]
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20230314203901.20803-1-krzysztof.kozlowski@linaro.orgSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-pltfm.c

@@ -54,7 +54,6 @@ static bool sdhci_wp_inverted(struct device *dev)
 #endif /* CONFIG_PPC */
 }
 
-#ifdef CONFIG_OF
 static void sdhci_get_compatibility(struct platform_device *pdev)
 {
 	struct sdhci_host *host = platform_get_drvdata(pdev);
@@ -72,9 +71,6 @@ static void sdhci_get_compatibility(struct platform_device *pdev)
 	    of_device_is_compatible(np, "fsl,mpc8536-esdhc"))
 		host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;
 }
-#else
-void sdhci_get_compatibility(struct platform_device *pdev) {}
-#endif /* CONFIG_OF */
 
 void sdhci_get_property(struct platform_device *pdev)
 {