Well, if you think about it, there are three options:
First
You could call the Emirates office in New York and ask them (or wherever you booked your ticket) if tip is included. Or ask them the name of the service company and then ask them.
Second
You could part with $10 (x2) to tip your driver.
Third
You do nothing. No tip, no sweat.
Although this is unsolicited, if you were to ask me what I would recommend, I would call Emirates, see if their tip is included. If it is, I would tell the driver upon pick up that you were told his tip was included and that you are carrying no cash on you (even if it is a fib). If their tip isn't included, I would part with $20 ($10x2, there and back) and chalk it up to being one of those who appreciates others serving him.