FT: Fix FTIE generation for 4-way handshake after FT protocol run

FT: Fix FTIE generation for 4-way handshake after FT protocol run

wpa_insert_pmkid() did not support cases where the original RSN IE
included any PMKIDs. That case can happen when PTK rekeying through
4-way handshake is used after FT protocol run. Such a 4-way handshake
used to fail with wpa_supplicant being unable to build the EAPOL-Key msg
2/4.

Fix this by extending wpa_insert_pmkid() to support removal of the old
PMKIDs, if needed.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>