Clear EAPOL authWhile and heldWhile values when port is disabled

Clear EAPOL authWhile and heldWhile values when port is disabled

IEEE Std 802.1X-2004 does not clear authWhile and heldWhile in this
case, but doing so allows the timer tick to be stopped more quickly when
the port is not enabled. Since these variables are used only within HELD
and RECEIVE states, clearing them on initialization does not change
actual state machine behavior. This reduces some unnecessary operations
in port disabled state and cleans up the wpa_supplicant debug log after
disconnection.

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