wifi: Legacy HAL Thermal API stub

Add the stub implementation for Wifi thermal API

Bug: 140311866
Test: Manual, on device
Change-Id: I401bf7a38fa52d160ae45cd519a225c07360cd3c
diff --git a/wifi/1.4/default/wifi_legacy_hal.cpp b/wifi/1.4/default/wifi_legacy_hal.cpp
index ae3c447..6f088d7 100644
--- a/wifi/1.4/default/wifi_legacy_hal.cpp
+++ b/wifi/1.4/default/wifi_legacy_hal.cpp
@@ -824,6 +824,13 @@
                                                     mode);
 }
 
+wifi_error WifiLegacyHal::setThermalMitigationMode(
+    const std::string& iface_name, wifi_thermal_mode mode,
+    uint32_t completion_window) {
+    return global_func_table_.wifi_set_thermal_mitigation_mode(
+        getIfaceHandle(iface_name), mode, completion_window);
+}
+
 std::pair<wifi_error, uint32_t> WifiLegacyHal::getLoggerSupportedFeatureSet(
     const std::string& iface_name) {
     uint32_t supported_feature_flags;