(Reuters) – Apple Incs shares rose slightly on Tuesday after the iPhone maker clarified its margin outlook by saying it would defer $900 million of revenue during the key Christmas holiday period, prompting analysts to raise price targets on the stock. Apple shares were up about 0.5 percent in early trading after dropping as much as 5 percent in extended trading on Monday when the company reported fourth-quarter results. We think that the stock initially exhibited weakness after the report partly due to concerns about the first-quarter gross margin guidance (36.5-37. …