qcacmn: Use a memory limit for Tx monitor feature

To avoid any crash/issues due to low memory, a limit
can be specified by the user for each soc.

Change-Id: I5a54b2d8af3769042720f85d0759b487c44e8fcc

dp/wifi3.0/monitor/dp_mon.h

@@ -653,6 +653,10 @@ struct dp_mon_soc {
 				   uint32_t mac_id,
 				   uint32_t quota);
 #endif
+
+#ifdef WLAN_TX_PKT_CAPTURE_ENH
+	struct dp_soc_tx_capture dp_soc_tx_capt;
+#endif
 };
 
 struct  dp_mon_pdev {