linux-wandboard

9p: encapsulate version function

Alsmot all 9P client wire functions have their own (set of) functions.
Tversion is an exception as its encapsulated into the client_create code.

This patch moves the protocol specifics of this to a function to match the
rest of the code.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>