OCE: RSSI-based rejection to consider Authentication frames (AP)

Try to make RSSI-based rejection of associating stations a bit less
likely to trigger false rejections by considering RSSI from the last
received Authentication frame. Association is rejected only if both the
Authentication and (Re)Association Request frames are below the RSSI
threshold.

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

src/ap/sta_info.h

@@ -217,6 +217,7 @@ struct sta_info {
 	u8 cell_capa; /* 0 = unknown (not an MBO STA); otherwise,
 		       * enum mbo_cellular_capa values */
 	struct mbo_non_pref_chan_info *non_pref_chan;
+	int auth_rssi; /* Last Authentication frame RSSI */
 #endif /* CONFIG_MBO */
 
 	u8 *supp_op_classes; /* Supported Operating Classes element, if