arm: mvebu: clearfog: enable eMMC boot partitions support

The Clearfog SOM can optionally have eMMC installed. Enable support for
eMMC boot partitions by default.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NStefan Roese <sr@denx.de>

include/configs/clearfog.h

@@ -29,6 +29,10 @@
  */
 #define CONFIG_SYS_MMC_BASE		MVEBU_SDIO_BASE
 
+#ifdef CONFIG_CMD_MMC
+#define CONFIG_SUPPORT_EMMC_BOOT
+#endif
+
 /* USB/EHCI configuration */
 #define CONFIG_EHCI_IS_TDI