Last updated March 1st, 2018.
These are binary deliverables for a basic RPi3 ATF, equivalent to https://github.com/andreiw/raspberry-pi3-atf/commit/64e7f333623e24d89f7dae37557d707b42689e50
If you want to use your own build, simply override ATF_BUILD_DIR, e.g.:
build -p RaspberryPiPkg/RaspberryPiPkg.dsc -D ATF_BUILD_DIR=$PWD/raspberry-pi3-atf/build/rpi3/debug