[dpdk-dev] Add option to dpdk-devbind.py to restore kernel driver binding

[Tosatti, Giovanni]

Hi all,
I'm new to this list.
I have a use case that required me to do a small enhancement to the dpdk-devbind.py script.
In particular I found very useful to have a --restore option that will unbind all devices currently bound to DPDK PMDs back to the kernel driver.
The patch is in attachment... would you consider merging that into upstream?

Thanks,
Giovanni Tosatti