pf: add DIOCGETSTATESV2

Add a new version of the DIOCGETSTATES call, which extends the struct to
include the original interface information.

MFC after: 1 week
Sponsored by: Rubicon Communications, LLC ("Netgate")
Differential Revision: https://reviews.freebsd.org/D31097

(cherry picked from commit c6bf20a2a46dc36bf881ac594454f71379828a9a)