Currently, you can only do it programmatically using Cordova net.yoik.cordova.plugins.screenorientation plugin.
It uses a simple syntax:
// set to either landscape
screen.lockOrientation('landscape');
// allow user rotate
screen.unlockOrientation();
Find more about it here, including a working example you can play with: Gajotres - Best Technology Product Reviews, News, Tips, and Comparison