Armv7-a performance slower than other deepinglearning framework

@merrymercy I looked it just now. I find it only tunes for some devices. If my device doesn’t support RPC (for example, my remote device doesn’t hav Python environment and can not set up RPC environment), what I can do is export the nnvm graph model / lib.so / param weights and run it in the device. How can I leverage your work and tune it? Thanks in advance.