from this link https://www.raspberrypi.org/forums/viewtopic.php?t=113602
cd /tmp
git clone http://github.com/raspberrypi/userland
cd userland
./buildme
That will put tvservice in /opt/vc/bin you may want to create a link from there to /usr/bin/tvservice
sudo ln -s /opt/vc/bin/tvservice /usr/bin/tvservice