If you set Tetra's clock to External in the Global menu this should do what you want, provided Ableton is sending clock out on Tetra's MIDI channel.
One thing to note, the sequencer and the arpeggiator will not run without the presence of a clock when set to External. If you're going to use Tetra in standalone mode or any other situation where it is not receiving clock externally, change the Global clock setting back to Internal.