If anyone would like to play with HDMI before cm merges the change.
1. Download liboverlay.so from
http://xda.shantur.com/test/liboverlay.so
2. Replace it with /system/lib/liboverlay.so
3. Reboot
After reboot you have to do the Peter-Panda-Dance for hdmi to work properly
1. Connect usb power and HDMI to mhl adapter.
2. Connect mhl adapter to phone and wait for a weird display
3. Press power off button to sleep and again to wake up, notice the display change.
4. Disconnect mhl and reconnect mhl to phone and voila fully working hdmi on CM.
5. Be happy