Add dtim config optimization HAL API

Test: compilation and halutil test
Bug: 170678227
Change-Id: I4f7535a70e53bd55f02b70867d071c440ad1529f
diff --git a/wifi/1.5/default/wifi_legacy_hal.cpp b/wifi/1.5/default/wifi_legacy_hal.cpp
index e1a5a8c..3e65ee0 100644
--- a/wifi/1.5/default/wifi_legacy_hal.cpp
+++ b/wifi/1.5/default/wifi_legacy_hal.cpp
@@ -1630,6 +1630,12 @@
                                                    configId);
 }
 
+wifi_error WifiLegacyHal::setDtimConfig(const std::string& iface_name,
+                                        uint32_t multiplier) {
+    return global_func_table_.wifi_set_dtim_config(getIfaceHandle(iface_name),
+                                                   multiplier);
+}
+
 void WifiLegacyHal::invalidate() {
     global_handle_ = nullptr;
     iface_name_to_handle_.clear();