arm: socfpga: Enable env support on MCV

Enable support for env in eMMC on MCV SoM.

Signed-off-by: Marek Vasut <marex@denx.de>

include/configs/socfpga_mcvevk.h

@@ -43,7 +43,11 @@
 #define CONFIG_LOADADDR		0x01000000
 #define CONFIG_SYS_LOAD_ADDR	CONFIG_LOADADDR
 
-#define CONFIG_ENV_IS_NOWHERE
+/* Environment is in MMC */
+#define CONFIG_ENV_OVERWRITE
+#define CONFIG_ENV_IS_IN_MMC
+#define CONFIG_SYS_MMC_ENV_DEV		0	/* device 0 */
+#define CONFIG_ENV_OFFSET		512	/* just after the MBR */
 
 /* USB */
 #ifdef CONFIG_CMD_USB