Er, sorry for my bad engrish..
That datasheet isn't exactly the gp2x cpu's one, it's the gp2x dev board's one. The dev board isn't specifically made for the gp2x, it's a bit generic for dvd players, car computers, things like that, and so it has these features built-in. It's possible that the gp2x has that, but I doubt it. Also note one thing: in these sheets says that the cpu with 2D, divx, etc extensions is the 920, the MAIN processor, and in the gp2x the graphic processor is the 940... I think Gamepark will put generic 940 and 920 cpu's without these extensions.