qcacld-3.0: Add debugfs support for roam scan stats

Add debugfs entry to get last five roam scan stats info which includes
old bssid, new bssid, roaming candidates etc., for STA interface.

Change-Id: Ied66beb270d97b6e17a6116c1be0e82783094519
CRs-Fixed: 2203885
diff --git a/core/wma/inc/wma.h b/core/wma/inc/wma.h
index 0199797..4388644 100644
--- a/core/wma/inc/wma.h
+++ b/core/wma/inc/wma.h
@@ -835,6 +835,7 @@
  * @vdev_stop_wakelock: wakelock to protect vdev stop op with firmware
  * @vdev_set_key_wakelock: wakelock to protect vdev set key op with firmware
  * @channel: channel
+ * @roam_scan_stats_req: cached roam scan stats request
  *
  * It stores parameters per vdev in wma.
  */
@@ -924,6 +925,7 @@
 	struct roam_synch_frame_ind roam_synch_frame_ind;
 	bool is_waiting_for_key;
 	uint8_t channel;
+	struct sir_roam_scan_stats *roam_scan_stats_req;
 };
 
 /**