wlan: Cache last connection info

Currently last connection info is not getting cached, so when
GETBSSINFO command comes information is extracted from current
conn_info which does not contain all the information required
as this information is cleared after disconnection.

To address this issue cache the connection info before
clearing it.

Change-Id: I3ec13264f97e7a4d0dc4699b463074062d087e82
CRs-Fixed: 2188187
diff --git a/CORE/HDD/inc/wlan_hdd_main.h b/CORE/HDD/inc/wlan_hdd_main.h
index 15327de..fdb877f 100644
--- a/CORE/HDD/inc/wlan_hdd_main.h
+++ b/CORE/HDD/inc/wlan_hdd_main.h
@@ -828,6 +828,8 @@
    /**Connection information*/
    connection_info_t conn_info;
 
+   connection_info_t cache_conn_info;
+
    roaming_info_t roam_info;
 
 #if  defined (WLAN_FEATURE_VOWIFI_11R) || defined (FEATURE_WLAN_ESE) || defined(FEATURE_WLAN_LFR)