Skimming the data sheet, it looks like you'd need to provide a different clock signal for the chip. There are two clock inputs possible, and software register to switch between them. Might want to look at the wiring diagrams on the wiki and see if the other clock pin can be accessed. Ignoring the difficultly in doing this, you might be able to provide another clock signal for 48khz.
Can I ask why you want this though? Theres no meaningful advantage to 48KHz, and if you need it for compatibility with other software, there are fast and extremely high quality resamplers available. IMO a mod like this is a solution in search of a problem.