In my project I am providing primarily Linux support, and eventually the hardware manufacturer discovered that uboot was explicitly disabling the SGX component. Once that was fixed, the SGX became functional.
One note, though, is that because the IPNC uses different stuff in the VPSS, this only works with FBDEV=no. This way only pvrsrvkm.ko and omaplfb.ko are required. No vpss.ko, nor ti81hdmi.ko are required. For rendering you need to use egl calls and render to a pixmap. Lookaround for the gleslayer code from TI for examples of how to configure it.