datapath: Fix kernel style issues.

Suggested-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
Add IPv6 support for OpenFlow, OVSDB, NetFlow, and sFlow.

Does not add IPv6 support for in-band control.

Co-authored-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Nandan Nivgune <nandan.nivgune@calsoftinc.com>
Signed-off-by: Abhijit Bhopatkar <abhijit.bhopatkar@calsoftinc.com>
Signed-off-by: Arun Sharma <arun.sharma@calsoftinc.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>