of12: set default args for FlowMod

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
of13: set default args for FlowMod

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>