Enables support for ext4, the "load" command, and using bootz with raw initrds.

Index: u-boot/include/configs/mx53loco.h
===================================================================
--- u-boot.orig/include/configs/mx53loco.h
+++ u-boot/include/configs/mx53loco.h
@@ -43,6 +43,8 @@
 #define CONFIG_GENERIC_MMC
 #define CONFIG_CMD_FAT
 #define CONFIG_CMD_EXT2
+#define CONFIG_CMD_EXT4
+#define CONFIG_CMD_FS_GENERIC
 #define CONFIG_DOS_PARTITION
 
 /* Eth Configs */
@@ -92,6 +94,7 @@
 /* Command definition */
 #include <config_cmd_default.h>
 #define CONFIG_CMD_BOOTZ
+#define CONFIG_SUPPORT_RAW_INITRD
 
 #undef CONFIG_CMD_IMLS
 
