I can confirm for a Chinese iPhone 5 that iOS 6.1 upgrade from iTunes indeed solves this hard coded google.cn search provider problem of Safari. if it does not solve at first, close Safari, go to Settings -> international, change to UK or US(or any) then back to your country, Open Safari and search sth. in Search box, if not Go to safari settings and clear everything, and try the above steps again.. Wroked for me...