I doubt such a certification would have any correlation with ability. Maybe the platonic ideal of training and testing that you're thinking of, but not a certification written by the US government. Even competent parts of the government like NIST take forever to update their standards. It would be worse for a licensing bureau with practically no in-house software expertise.

You can get a computer engineering PE, which would probably be appropriate for the vast majority of embedded software developers. There was a software PE for a few years, but my understanding is that it was dropped for lack of interest.