qcacld-3.0: Refine the extscan set significant change logic

Make the following updates to the extscan set significant change
logic:
1) Exclusively use the Unified WMI data structures.
2) Update the HDD<=>SME interface to enforce the contract that SME
   must not make any assumptions about the buffers provided by HDD.

Change-Id: I916f387cee254c2d8ba57a9182bd927a91eadf0c
CRs-Fixed: 2307374
diff --git a/core/wma/inc/wma_internal.h b/core/wma/inc/wma_internal.h
index b806e76..929d20d 100644
--- a/core/wma/inc/wma_internal.h
+++ b/core/wma/inc/wma_internal.h
@@ -386,9 +386,18 @@
 QDF_STATUS wma_extscan_stop_hotlist_monitor(tp_wma_handle wma,
 			struct extscan_bssid_hotlist_reset_params *params);
 
-QDF_STATUS wma_extscan_start_change_monitor(tp_wma_handle wma,
-					    tSirExtScanSetSigChangeReqParams *
-					    psigchange);
+/**
+ * wma_extscan_start_change_monitor() - send start change monitor cmd
+ * @wma: wma handle
+ * @params: change monitor request params
+ *
+ * This function sends start change monitor request to fw.
+ *
+ * Return: QDF status
+ */
+QDF_STATUS
+wma_extscan_start_change_monitor(tp_wma_handle wma,
+			struct extscan_set_sig_changereq_params *params);
 
 QDF_STATUS wma_extscan_stop_change_monitor(tp_wma_handle wma,
 		   tSirExtScanResetSignificantChangeReqParams *pResetReq);