net/virtio: add in-order Rx/Tx into selection

net/virtio: add in-order Rx/Tx into selection

After IN_ORDER Rx/Tx paths added, need to update Rx/Tx path selection
logic.

Rx path select logic: If IN_ORDER and merge-able are enabled will select
IN_ORDER Rx path. If IN_ORDER is enabled, Rx offload and merge-able are
disabled will select simple Rx path. Otherwise will select normal Rx
path.

Tx path select logic: If IN_ORDER is enabled will select IN_ORDER Tx
path. Otherwise will select default Tx path.

Signed-off-by: Marvin Liu <yong.liu@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>