UPL requires the Shim Layer, and those patches exist in the `starlabsltd` fork. Set the repository to custom, to allow this fork and branch to be selected correctly. Signed-off-by: Sean Rhodes <sean@starlabs.systems> Change-Id: Ieca72498bde51a184d689670449b66ccc78d658a Reviewed-on: https://review.coreboot.org/c/coreboot/+/81277 Reviewed-by: Benjamin Doron <benjamin.doron00@gmail.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Paul Menzel <paulepanter@mailbox.org> Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>