qcacmn: Add API to get 2GHz/5GHz freq range and wireless modes

Offload layer uses low and high 2GHz/5GHz freq ranges and chip
supported wireless modes to populate umac ic channel list.

Change-Id: I899edd83548d68e67659b3a9273ddaaaf740540b
CRs-Fixed: 2047212

target_if/regulatory/src/target_if_reg.c

@@ -148,6 +148,9 @@ QDF_STATUS target_if_register_regulatory_tx_ops(struct wlan_lmac_if_tx_ops
 		tgt_if_regulatory_unregister_master_list_handler;
 
 	reg_ops->set_country_code = tgt_if_regulatory_set_country_code;
+
+	reg_ops->fill_umac_legacy_chanlist = NULL;
+
 	return QDF_STATUS_SUCCESS;
 }