Mathematics is just our language of choice in understanding the nature of extreme efficiency with energy and material creation. I'm sure there are many older universes with a much more clunky system of operation, and plenty more that use even higher efficiency levels that are not based on light but something we can't even comprehend.
Whether it proves god or not is more based on what you define god to be. It certainly proves the principles of design to me, though i'm sure plenty of so called scientists will deny it in favor of accidental chaos theories.
The above equation though, presumes light was created...I can't agree with that idea, I could be wrong but I see light as the perfected balance of frequency and geometry ratios, light itself is just the totality of this basic foundation.