OpenFlow Spec does not allow to filter flow entries by priority,
but when with a large amount of flow entries, filtering by priority
is convenient to get statistics efficiently.
This patch enables lib/ofctl_v_* modules to filter flow stats by
priority.
This patch is suggested by China Shenzhen TICOMM Information
Technology Co. Ltd.
Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>