After porting u-boot to your i.MX5x board you might want add it on LTIB menu, "Choose your board for u-boot" section. For this, edit ltib/config/platform/imx/main.lkc to add your board:
Enter board on menu:
comment "Choose your board for u-boot"
choice
prompt "board"
default BOARD_MX51_BBG
depends on PLATFORM = "imx51"
help
This menu will let you choose the board you use.
...
+ config BOARD_MX53_MYBOARD
+ bool "mx53_myboard"
...
endchoice
Add the "mx53_myboard_config" that matches your board configuration on the u-boot Makefile to PKG_U_BOOT_CONFIG_TYPE:
config PKG_U_BOOT_CONFIG_TYPE
string
...
+ default "mx53_myboard_config" if ( PLATFORM = "imx51" && BOARD_MX53_MYBOARD && !PKG_KERNEL_UPDATER )
...
