Well I would suspect that you could port it to an embedded system provided you had:
1) Either an OpenGL and X implementation on tha system or another graphics backend you knew enough about to write an irrlicht renderer for
2) A libJpeg implementation and a zlib implementation on the embedded system, though these could be dropped from irrlicht if you need to cut down the size.
3) Depending on what OS your are using on the embedded system, you may need to make extensive changes to the core functionality of irrlicht.
Niko has made porting irrlicht a fairly excessible task, so if you have it enough thought and effort it should be possible, depending on the limitations of your embedded syste and your coding abilties