V2 Feedback from John Hughes.
- Add header for userspace implementations such as xot/xoe to use
- Use explicit values for interface stability
- No changes to driver patches

V1
- Use identifiers instead of magic numbers for X25 layer 3 to device interface.
- Also fixed checkpatch notes on updated code.

[ Add new user header to include/linux/Kbuild  -DaveM ]
Signed-off-by: NAndrew Hendry <andrew.hendry@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>