Bug 6633 : NXM_OF_IN_PORT support in openflowplugin

Bug 6633 : NXM_OF_IN_PORT support in openflowplugin

Description : OVS split-horizon logic will drop pkts by default if value
of in_port and out_port is same. But, if we have two vlan-trunk member
VM for which trunk interface is same, the connectivity between these two
VM cannot be established as OVS drops such packets. So, it is required to
override the value of in_port so that split_horizon check is bypassed.
Nicra NXM_OF_IN_PORT support is required in order to achieve this. The
in_port value will be overrriden using load(ex:
load:0x1->NXM_OF_IN_PORT[]).

Change-Id: Ica0a1b2da27fc189b8906462a4420473215a22af
Signed-off-by: xcheara <chetan.arakere@altencalsoftlabs.com>