Your best bet is not to identify what part it is, but what function it had and replace that function. You will have to unsolder the part anyway. After that, you can start working out if and how it is connected to the USB port. If it is, you know what it does and can replace it with something else. 

It is possible USB might work after you unsolder the part. Perhaps it is just some peripheral part, not the power supply to USB. In this case, the fried part might just short USB power, which then shuts down. 

If not, maybe (danger!) you can connect the USB 5V directly with Mainboard 5V from, say the harddisk plug. This would change how safe USB is (usually it is limited to a certain amperage), and you could fry the notebook with USB. But then again it is already toasted...