wlan: Do not create preauth node while sending SAE assoc reject

Driver validates the authentication context and allows
connection with SAE AKM in either of the below cases,
1. Successful SAE authentication
2. Open authentication with a valid PMKID

Driver rejects association if none of these are met. Do not
create preauth node while sending assoc reject in these cases
as there is no need to maintain a preauth context. Stations
initiate a fresh SAE authentication in both of these cases and
a new node will be created.

Change-Id: Ic446add47358d01bf4b316aa9ac5bf86c33bf812
CRs-Fixed: 2734690