Send a canonical IPv4 prefix in table 60 routing rules

Send a canonical IPv4 prefix in table 60 routing rules

Testing with userspace OVS with DPDK uncovered that the routing
rules that go into table 60 were getting rejected.

Messages from ovs-vswitchd.log:

... |nx_match|WARN|Rejecting NXM/OXM entry
    0:32768:12:1:8 with 1-bits in value for bits wildcarded by the mask.

... |connmgr|INFO|br-int<->tcp:10.11.21.7:6653:
    sending OFPBMC_BAD_WILDCARDS error reply to OFPT_FLOW_MOD message

Clearing the non-prefix bits resolved the problem and the flows were
successfully added.

v2 - split up long line into two more readable lines

Change-Id: I42a0c63e6e837197d29bb8333f12e822a5f15d91
Signed-off-by: Eric Multanen <eric.w.multanen@intel.com>