We only know that one specific Klingon had two. And those Klingons appear to be a different species from Worf since we've seen Klingons from before and after the Discovery era and they either looked like Worf or TOS Klingons, which were the wrinkle forehead Klingons augmented with the same genetic augments as Khan according to Enterprise. There is a fan theory that I like that the Klingon Empire is actually more than one species, like the Xindi, which fight for control.
When worf got hit by that barrel and was paralyzed for an episode, they definitely mentioned that Klingons and an unusual number of duplicate organs due to their violent history.
It doesn't explicitly state double dongs, but it does imply it.