clang: fix undeclared identifier

Included config header file to resolve the following error after
recent build version upgrade.

'''
error: use of undeclared identifier 'FAULTLOG_DUMP_PATH' [clang-diagnostic-error]
'''

Change-Id: I140c0074104bd65387d2b3621c580fd4fecd9849
Signed-off-by: Jayanth Othayoth <ojayanth@gmail.com>
diff --git a/dump_manager_faultlog.hpp b/dump_manager_faultlog.hpp
index 457c4fe..a0c3a30 100644
--- a/dump_manager_faultlog.hpp
+++ b/dump_manager_faultlog.hpp
@@ -1,5 +1,7 @@
 #pragma once
 
+#include "config.h"
+
 #include "dump_manager.hpp"
 
 #include <phosphor-logging/elog-errors.hpp>