Ah… I see.
The AOSP builds are rather experimental (they are based on upstream AOSP, an upstream(ish) LTS kernel and smallest amount of glue code possible… this is very different to a typical vendor port of Android). They rely on the same upstream focused drivers that we use for the GNU/Linux builds. I’m afraid that means whilst compatibility with Android itself should be very good it also means that there is no support for the Qualcomm vendor extensions and drivers because we are not using these drivers.
Unfortunately SNPE relies on these to function. SNPE works internally by spreading the load between CPU, GPU and DSP and, with the current AOSP images, I think only the CPU execution engine will be available (and even that may refuse to load).