Its a natural double major to do. I almost did it myself, but decided I liked math a lot more so I just took a lot more math classes. Going into graduate school the physics would have been no advantage to me for what I will be doing, but if I wanted to major in something else in graduate school or get certain jobs the physics may have helped.
So basically, if you want to do it do it. If you think you should do it because you think it will make you look smarter to graduate schools or something, dont.
So basically, if you want to do it do it. If you think you should do it because you think it will make you look smarter to graduate schools or something, dont.