of14: Correct documentation of table mod flags and properties

* Document properties
* The valid flags for OpenFlow 1.4 are OFPTC_EVICTION and OFPTC_VACANCY_EVENTS

Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>