bitbake is located in 'edison-src/device-software/utils/poky-daisy-11.0.0.tar.bz2' (depends on platform) and is 'installed' as part of the setup process.
I used quotes around 'installed' because bitbake is just extracted to 'edison-src/poky/...." and is then placed in your linux PATH when you run the 'source poky/oe-init-build-env' command.