clang-tidy: Enable modernize-deprecated-headers check

Some headers from C library were deprecated in C++ and are no
longer welcome in C++ codebases. Some have no effect in C++ [1].

[1]: https://releases.llvm.org/13.0.1/tools/clang/tools/extra/docs/clang-tidy/checks/modernize-deprecated-headers.html

Change-Id: Ia3b1df10175e2e661c8fffb82e357c9db81b2e9c
Signed-off-by: Pavithra Barithaya <pavithrabarithaya07@gmail.com>
diff --git a/libpldmresponder/test/libpldmresponder_base_test.cpp b/libpldmresponder/test/libpldmresponder_base_test.cpp
index 4656882..539d2cf 100644
--- a/libpldmresponder/test/libpldmresponder_base_test.cpp
+++ b/libpldmresponder/test/libpldmresponder_base_test.cpp
@@ -4,11 +4,11 @@
 #include "test/test_instance_id.hpp"
 
 #include <libpldm/base.h>
-#include <string.h>
 
 #include <sdeventplus/event.hpp>
 
 #include <array>
+#include <cstring>
 
 #include <gtest/gtest.h>
 
diff --git a/libpldmresponder/test/libpldmresponder_bios_table_test.cpp b/libpldmresponder/test/libpldmresponder_bios_table_test.cpp
index 47764ee..7aa143e 100644
--- a/libpldmresponder/test/libpldmresponder_bios_table_test.cpp
+++ b/libpldmresponder/test/libpldmresponder_bios_table_test.cpp
@@ -1,8 +1,7 @@
 #include "libpldmresponder/bios_table.hpp"
 
-#include <stdlib.h>
-
 #include <algorithm>
+#include <cstdlib>
 #include <vector>
 
 #include <gtest/gtest.h>
diff --git a/libpldmresponder/test/libpldmresponder_bios_test.cpp b/libpldmresponder/test/libpldmresponder_bios_test.cpp
index 2b9e49a..c229caa 100644
--- a/libpldmresponder/test/libpldmresponder_bios_test.cpp
+++ b/libpldmresponder/test/libpldmresponder_bios_test.cpp
@@ -3,7 +3,6 @@
 
 #include <libpldm/base.h>
 #include <libpldm/bios.h>
-#include <string.h>
 
 #include <array>
 #include <cstring>