qcacmn: update average rssi in scan entry

If elapsed time since last rssi update for a particular
scan entry is smaller than a thresold, calculate a
running average of the RSSI values. Otherwise last RSSI
is more representive of the signal strength.

Change-Id: I4cbecc8b6bfbb73c272544114b063b25c26e14fe
CRs-Fixed: 1095299
diff --git a/umac/scan/dispatcher/src/wlan_scan_utils_api.c b/umac/scan/dispatcher/src/wlan_scan_utils_api.c
index eb940b4..4f224e2 100644
--- a/umac/scan/dispatcher/src/wlan_scan_utils_api.c
+++ b/umac/scan/dispatcher/src/wlan_scan_utils_api.c
@@ -575,6 +575,7 @@
 		(le16toh(*(uint16_t *)hdr->i_seq) >> WLAN_SEQ_SEQ_SHIFT);
 
 	scan_entry->rssi_raw = rx_param->rssi;
+	scan_entry->avg_rssi = WLAN_RSSI_DUMMY_MARKER;
 	scan_entry->tsf_delta = rx_param->tsf_delta;
 
 	/* store jiffies */
@@ -593,10 +594,8 @@
 		bcn->timestamp, 8);
 	scan_entry->erp = ERP_NON_ERP_PRESENT;
 
-
-	scan_entry->rssi_timestamp =
-		scan_entry->scan_entry_time =
-			qdf_mc_timer_get_system_time();
+	scan_entry->scan_entry_time =
+		qdf_mc_timer_get_system_time();
 
 	scan_entry->raw_frame.len = frame_len;
 	qdf_mem_copy(scan_entry->raw_frame.ptr,