BOSTON/LONDON (Reuters) -Some trade policy relief and strong bank earnings helped push Wall Street up slightly on Tuesday, while U.S. government bonds and the dollar were steady, after U.S. President Donald Trump touted possible tariff changes on autos. Trump said on Monday he was considering a modification to the 25% tariffs imposed on foreign auto and auto parts imports from Mexico, Canada and other places. The main U.S. stock indexes ticked higher on Tuesday, with Bank of America, Citigroup and Wells Fargo gaining after the trio of banking giants posted strong profits for the first quarter.