Correct the 802.11s mesh configuration structure and related tidbits.

Correct the 802.11s mesh configuration structure and related tidbits.

* Change the mesh IE size to be IEEE80211_MESH_CONF_SZ rather than the
  size of the structure;
* conf_cap is now a uint8_t rather than a uint16_t (uint16_t in D3.0,
  uint8_t in the amendment spec);
* Update mesh config capability bits - earlier bits were from draft X,
  current is amendment spec;
* Update the following to be an enum rather than #define and added
  a VENDOR entry too from the amendment spec;
  IEEE80211_MESHCONF_PATH_*
  IEEE80211_MESHCONF_METRIC_*
  IEEE80211_MESHCONF_CC_*
  IEEE80211_MESHCONF_SYNC_*
  IEEE80211_MESHCONF_AUTH_*
* Kept IEEE80211_MESHCONF_FORM_* and IEEE80211_MESHCONF_CAP_* as
  defines because they are defined in a way that we need to mask in/out
  information;
* In IEEE80211_MESHCONF_CAP_* IEEE80211_MESHCONF_CAP_TBTTA is removed
  and 0x80 is made reserved as defined in the amendment spec.

Submitted by:	monthadar@gmail.com
Reviewed by:	rpaulo