Hi Sam,
once you install the BSP, you can just run following to unpack, build and deploy u-boot sources:
./ltib -m prep -p u-boot
./ltib -m scbuild -p u-boot
./ltib -m scdeploy -p u-boot
In later BSPs there should be detailed instructions how to build u-boot also separately from LTIB. Attached file should be in the BSP release for i.MX35.
BR,
Vladan