NPU documentation and tools

Hi @Frank
No changes had been made on our NPU code. The only different is that we had connected our custom-designed camera board into the CSI port of the VIM 3.
Thank

@thanhhc Can you try with the original camera ? If the code hasn’t changed, it could have been a camera problem at first

@Frank
It turns out that I had made changes in the kernel image and dtb file during developing video driver for our camera board. We had rolled back the kernel and the error was fixed.
Thank for your support
Thanh