We were told our daughter had a clicky hip too. The paed in the hospital told us when he checked her after she was born. He booked in an ultrasound for when she was 6 weeks old. After I went home from hospital, and the nurse came round to our place to check on us, I think she heard just a small click in her hip.
We went along to the ultrasound, and they found that both of her hips were just fine. We had our 6 week checkup the following day and got our GP to check her hips. He advised us they were fine and he was unable to find a click. So, we never did anything about it as we were told there was no problem. We got told lots of babies have "clicky hips" when born and it often fixes itself in the first couple of months.