qcacld-3.0: Add support to get per chain rssi stats

Propagation from qcacld-2.0 to qcalcd-3.0.

Add support to get per chain rssi from fw via
already existing WMI command WMI_REQUEST_STATS_CMDID
and then store it in the station_info structure defined
by cfg80211.

Change-Id: Id50c96dd322b5ca4db34cf2df901730d8b103251
CRs-Fixed: 1005367
diff --git a/core/wma/inc/wma_internal.h b/core/wma/inc/wma_internal.h
index b5fc9f4..dadac75 100644
--- a/core/wma/inc/wma_internal.h
+++ b/core/wma/inc/wma_internal.h
@@ -55,12 +55,14 @@
 #define FW_PDEV_STATS_SET 0x1
 #define FW_VDEV_STATS_SET 0x2
 #define FW_PEER_STATS_SET 0x4
-#define FW_STATS_SET 0x7
+#define FW_RSSI_PER_CHAIN_STATS_SET 0x8
+#define FW_STATS_SET 0xf
 
 /*AR9888/AR6320  noise floor approx value
  * similar to the mentioned the WMA
  */
 #define WMA_TGT_NOISE_FLOOR_DBM (-96)
+#define WMA_TGT_RSSI_INVALID      96
 
 /*
  * Make sure that link monitor and keep alive