Raichu delivering the goods. Notably, this is PDK0.8 (i.e. not final), and the voltage only goes up to 1.1V, which is pretty low. Assuming this represents ES2 silicon, I think final clock speeds in the mid-5GHz range for mobile chips are very reasonable.
That said, the VF curve is a bit weird. There's a spike for that last 0.02V, when you'd expect the opposite.