No, he can't. The needed mali userspace hasn't been published yet. The s905 and s905x are similar enough to support in a single build, the s912 is too different to do that. Which also means that anyone can copy the S905 subdir in LE to S912 and start hacking without having to coordinate with anyone. Provided the mali blob shows up soon.
Hmm.. What level of support is missing?
Are you saying that ARM haven't published MALI-T820 interfaces, or that Amlogic haven't released any devkit for the S912?