datapath-windows: Add PID Number attribute for port notification / Fix logic

[1] User mode OVS expects to have the PID number in the port state
    notification command
[2] Fix logic error-for-Windows-user-mode

Signed-off-by: Eitan Eliahu <eliahue@vmware.com>
Acked-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Sorin Vinturis <svinturis@cloudbasesolutions.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>