fix compile failure from missing header

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Iba39c222334451ee3f90b1523d68464e09a88292
diff --git a/src/kunlun_oem.cpp b/src/kunlun_oem.cpp
index c82fab3..83bdb19 100644
--- a/src/kunlun_oem.cpp
+++ b/src/kunlun_oem.cpp
@@ -1,4 +1,5 @@
 #include <filesystem>
+#include <fstream>
 #include <ipmid/api.hpp>
 #include <phosphor-logging/log.hpp>