wifi: brcmfmac: Fix to add brcmf_clear_assoc_ies when rmmod

Conn_info->req_ie/resp_ie is used to indicate the assoc_req_ies /
assoc_resp_ies to cfg80211 layer when connection is done. The buffer is
freed and allocated again at next connection establishment. The buffers
also needs to be freed at the timing of rmmod as well.

Signed-off-by: Wataru Gohda <wataru.gohda@cypress.com>
Signed-off-by: Chi-hsien Lin <chi-hsien.lin@cypress.com>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220722115632.620681-5-alvin@pqrs.dk