net: qrtr: Move constants to header file

The constants are used by both the name server and clients, so clarify
their value and move them to the uapi header.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 28978713)