clang-format: update to latest from docs repo

Since `Cpp11` is an alias for `Latest` and we should tend towards using the
latest C++ standard, update the C++ standard to Latest.

https://github.com/llvm/llvm-project/commit/e5032567903de19962333c4bf7d2edceaf4f9824#diff-b49a097415dff2837d9626d422c58ba8R82
https://github.com/openbmc/docs/blob/master/style/cpp/.clang-format

Also, other OpenBMC repos are doing the same.

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: I449e88bb4e1e262060110e1a8f3e8db3ddfc74cf
diff --git a/oem/ibm/test/libpldm_fileio_test.cpp b/oem/ibm/test/libpldm_fileio_test.cpp
index 275f295..10ba83f 100644
--- a/oem/ibm/test/libpldm_fileio_test.cpp
+++ b/oem/ibm/test/libpldm_fileio_test.cpp
@@ -1,10 +1,10 @@
+#include "libpldm/base.h"
+#include "libpldm/file_io.h"
+
 #include <string.h>
 
 #include <array>
 
-#include "libpldm/base.h"
-#include "libpldm/file_io.h"
-
 #include <gtest/gtest.h>
 
 constexpr auto hdrSize = sizeof(pldm_msg_hdr);