You cannot do this. Apple says that you cannot take away supporting a specific device type once you do it.
Developers who wish to issue updates, but remove device support, have
- Fix their app so that it can work on the devices they originally set out to support.
- Target a newer version of iOS that requires a newer device.
- Remove their app from the store, and upload the new app with a different bundle ID.
Apple’s recommendation (https://developer.apple.com/library/ios/qa/qa1623/_index.html) is to add the device support back, or remove the app from the store and upload it back as a new bundle id (not ideal). Option 2 above really doesn’t apply to what you are trying to do.