Colonel Worf could have been Mogh's father but it's never been written into any of the shows.
>>>I thought that was Worf, which was why he was always talking about Khitomer.
Well Khitomer was a Klingon colony before it was destroyed. In addition Colonel Worf should not be confused with Commander Worf from TNG and DS9, both characters are played by the same actor but Colonel Worf couldn't be Worf son Mogh because that would have made him around a 100 years old by the time of the events of DS9.
Actually, it could--because it has been established that Klingons have lifespans of a similar order to Vulcans. And, if I'm not mistaken, this is actually what the writers of Star Trek VI: The Undiscovered Country intended ProfessorTrek 08:38, August 6, 2011 (UTC)
Except Worf was not over 100 so no it's not the least bit possible. Also there's the fact that Colonel Worf was old by that point so in fact well, well over 100 which is why Colonel Worf is most certainly not Worf son of Mogh.
Worf in ST: VI is indeed Worf's grandfather, and namesake. http://memory-alpha.org/wiki/Worf_(Colonel)