Userspace needs to know the version of the interface implemented by a
client so it can create the proper command streams. Allow individual
drivers to store this version along with the client so that it can be
returned to userspace upon opening a channel.
Acked-by: NDmitry Osipenko <digetx@gmail.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>