wlan: Preferentially scan occupied channels (learned from previous scans).

Change-Id: I62561ceec46134c5ca6ccd82d3313768d309effc
CR-Fixed: 395375
diff --git a/CORE/HDD/inc/wlan_hdd_cfg.h b/CORE/HDD/inc/wlan_hdd_cfg.h
index a707ce1..8b1797e 100644
--- a/CORE/HDD/inc/wlan_hdd_cfg.h
+++ b/CORE/HDD/inc/wlan_hdd_cfg.h
@@ -1002,7 +1002,7 @@
 #define CFG_NEIGHBOR_LOOKUP_RSSI_THRESHOLD_DEFAULT   (120)
 
 #define CFG_NEIGHBOR_SCAN_CHAN_LIST_NAME                      "gNeighborScanChannelList"
-#define CFG_NEIGHBOR_SCAN_CHAN_LIST_DEFAULT                   "1,6"
+#define CFG_NEIGHBOR_SCAN_CHAN_LIST_DEFAULT                   ""
 
 #define CFG_NEIGHBOR_SCAN_MIN_CHAN_TIME_NAME                  "gNeighborScanChannelMinTime"
 #define CFG_NEIGHBOR_SCAN_MIN_CHAN_TIME_MIN                   (10)