The Hitachi SH7750 includes a number of integrated peripherals, but it doesn't have any sort of on-board graphics engine.
The 128-bit graphics processor used in the Dreamcast is actually an NEC PowerVR "VR2" chip.
PowerVR cards used to be available for the PC and were actually quite popular for a short while, but the 3DFX "Voodoo" card was generally considered the better solution and rapidly pushed the NEC chipset into relative obscurity.