mmc: Add Efinix eMMC driver

drivers/mmc/host/Kconfig

@@ -1109,3 +1109,15 @@ config MMC_SDHCI_EFX
 
 config MMC_SDHCI_EXTERNAL_DMA
 	bool
+
+config MMC_EFX_EMMC
+	tristate "Efinix eMMC host controller support"
+	depends on OF
+	help
+	  This selects support for the Efinix eMMC Host Controller.
+	  The controller supports eMMC 5.1 specification with HS200 and HS400 modes.
+	  It includes hardware reset support and is designed for embedded applications.
+
+	  If you have an Efinix platform with an eMMC device, say Y here.
+
+	  If unsure, say N.