I have just uploaded my first app to iTunes Connect and noticed that my list of supported devices is appearing as follows...
Device Requirements: Compatible with iPho
You can't restrict the app to not work on the iPad. Backwards compatibility with all iPhone apps is a feature of the iPad. Your app will run in a 100% frame or in an optional 2x mode depending on user preference.
iPhone OS apps that link against the 2.x or 3.x framework and test clean on the iPhone and iPod touch should work w/o any trouble on the iPad.
If you tested on the iPod, taking into account the lack of cell radio, camera, etc., you should be totally fine.