Do not trigger fast reconnection on locally generated deauth/disassoc

Do not trigger fast reconnection on locally generated deauth/disassoc

The deauthentication and disassociation events from nl80211 were being
processed identically regardless of whether the frame was generated by
the local STA or the AP. This resulted in fast reconnection mechanism
getting triggered even in the case where the disconnection was detected
locally (e.g., due to beacon loss) while this was supposed to happen
only in the case where the AP is sending an explicit Deauthentication
or Disassociation frame with a specific reason code.

Fix this by adding a new deauth/disassoc event variable to indicate
whether the event was generated locally.

Signed-hostap: Jouni Malinen <j@w1.fi>