qcacmn: Add support for lower span active and passive dwell time

Add LOW_SPAN_ACTIVE_DWELL_TIME and LOW_SPAN_PASSIVE_DWELL_TIME
macro support to keep all 2.4g/5g active/passive dwell time
same for low span scan mode.
Disable adaptive dwell to firmware so that firmware cannot
modify dwell time.

Change-Id: Iff05dd7b37a40226c61b28a1e59ea8aa8c57cb52
CRs-Fixed: 3076163

os_if/linux/scan/src/wlan_cfg80211_scan.c

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2017-2021 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2021 Qualcomm Innovation Center, Inc. All rights reserved.
  *
  * Permission to use, copy, modify, and/or distribute this software for
  * any purpose with or without fee is hereby granted, provided that the
@@ -1520,8 +1521,7 @@ int wlan_cfg80211_scan(struct wlan_objmgr_vdev *vdev,
 		if (req->scan_req.scan_policy_high_accuracy)
 			req->scan_req.adaptive_dwell_time_mode =
 						SCAN_DWELL_MODE_STATIC;
-		if (req->scan_req.scan_policy_low_power ||
-		    req->scan_req.scan_policy_low_span)
+		if (req->scan_req.scan_policy_low_power)
 			req->scan_req.adaptive_dwell_time_mode =
 						SCAN_DWELL_MODE_AGGRESSIVE;
 	}