Update ieee80211_sample and complete ieee80211_ratectl_none templete. (r257398)
* rename ieee80211_rc_sample* to ieee80211_sample*. this seems more harmonious.
* modify ieee80211_sample to let it use the latest net80211-ratectl features.
* fix some errors in ieee80211_sample.
* complete the ieee80211_ratectl_none templete with new added net80211-ratectl
  functions.