ofp-actions: Prepare to treat OF1.2 actions as OF1.1 actions.

ofp-actions: Prepare to treat OF1.2 actions as OF1.1 actions.

The numbering of OpenFlow 1.0 actions overlaps with the numbering
of OpenFlow 1.1+ actions, so the two sets of actions have to be
distinguished for input and output.  But OpenFlow 1.1 and 1.2
actions are numbered to avoid this problem, so there is no need
to distinguish them in the same way.  Therefore, this commit
prepares to treat them together.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Reviewed-by: Simon Horman <horms@verge.net.au>