common: code re-org

Move common files under a common/ directory.

Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
Change-Id: I0eaf91d4ee94c1e78228da0c50892f82e91912fa
diff --git a/libpldmresponder/fru.cpp b/libpldmresponder/fru.cpp
index b3dc73b..a9c8787 100644
--- a/libpldmresponder/fru.cpp
+++ b/libpldmresponder/fru.cpp
@@ -2,7 +2,7 @@
 
 #include "libpldm/utils.h"
 
-#include "utils.hpp"
+#include "common/utils.hpp"
 
 #include <systemd/sd-journal.h>