mx53loco: Select CONFIG_CMD_EXT4

Select the CONFIG_CMD_EXT4 option so that files can be loaded
from an ext4 partition.

Signed-off-by: Fabio Estevam <festevam@denx.de>
diff --git a/configs/mx53loco_defconfig b/configs/mx53loco_defconfig
index 08bcd35..d5f2b70 100644
--- a/configs/mx53loco_defconfig
+++ b/configs/mx53loco_defconfig
@@ -34,6 +34,7 @@
 CONFIG_CMD_MII=y
 CONFIG_CMD_PING=y
 CONFIG_CMD_EXT2=y
+CONFIG_CMD_EXT4=y
 CONFIG_CMD_FAT=y
 CONFIG_CMD_FS_GENERIC=y
 CONFIG_OF_CONTROL=y