Upgraded my device from KitKat to Lollipop, is there a way to get the airplane mode back to the power options?
This is the way Google wanted the power menu to work in Android Lollipop. It's just terribly inconvenient for those who used Android before. But if you really need to bring back the feature and have a rooted phone, you can try this method which works on Nexus.

But you don't need to go to the settings to enable Airplane mode. From the top of the screen, just swipe down twice or drag down once using two fingers to reveal the Airplane mode toggle.

It's the quickest way to use the Airplane mode in Lollipop. Some apps in play store(Power Toggles, Toggle Airplane) has shortcuts to enable Airplane mode but you need a rooted phone for that to work.