util: create util object for bmc and tool

Create a common util object for the BMC library and host tool.  Place in
blobs namespace favoring BMC.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I036fd65d924c65fcfa71aba5cd76275a2941ff14
diff --git a/test/firmware_createhandler_unittest.cpp b/test/firmware_createhandler_unittest.cpp
index 84769cb..65aa6ef 100644
--- a/test/firmware_createhandler_unittest.cpp
+++ b/test/firmware_createhandler_unittest.cpp
@@ -1,6 +1,7 @@
 #include "data_mock.hpp"
 #include "firmware_handler.hpp"
 #include "image_mock.hpp"
+#include "util.hpp"
 
 #include <phosphor-logging/test/sdjournal_mock.hpp>
 #include <sdbusplus/test/sdbus_mock.hpp>
@@ -25,7 +26,7 @@
     //    SwapJouralHandler(&journalMock);
 
     std::vector<HandlerPack> blobs = {
-        {FirmwareBlobHandler::hashBlobID, &imageMock},
+        {hashBlobId, &imageMock},
     };
 
     std::vector<DataHandlerPack> data = {