CMD: Drop CONFIG_CMD_EMMC, it's not used

$ git grep CMD_EMMC
include/configs/u8500_href.h:#define CONFIG_CMD_EMMC

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: dirk.behme@googlemail.com
Cc: helmut.raiger@hale.at
Cc: john.rigby@linaro.org
Cc: vapier@gentoo.org

include/configs/u8500_href.h

diff --git a/include/configs/u8500_href.h b/include/configs/u8500_href.h
index 4747fbd..95028de 100644
--- a/include/configs/u8500_href.h
+++ b/include/configs/u8500_href.h
@@ -95,7 +95,6 @@
 #define CONFIG_CMD_MMC
 #define CONFIG_CMD_FAT
 #define CONFIG_CMD_EXT2
-#define CONFIG_CMD_EMMC
 #define CONFIG_CMD_SOURCE
 #define CONFIG_CMD_I2C