Rdio has released an update to its on-demand subscription music streaming app for the iPhone and iPod touch adding native iPad support. With Rdio 1.2 users can now take advantage of a UI specifically designed for the iPad with high resolution artwork, playful on-screen controls, track listings and portrait and landscape support. As with the iPhone and iPod touch version, Rdio on the iPad also provides access to offline music listening, Rdio social…