I think the question would be stronger if you defined it better. Data? What data? At its most basic level yes data is important but only when used by skilled people. Data left sitting on a hard drive is useless, as is data that is used incorrectly. Human resources, along with any other department, need the correct data to function. Without it they are worthless. Your question can be considered similar to: which is more important in a car - petrol or engine? One without the other is useless.
who needs human resources without those humans having something to do, which requires data? what's human resources going to do without data to act on? who's going to gather and process data without human resources to handle hiring etc.?