add handler logic to handle SysCpldVersion

Add handler logic to handler for SysCpldVersion such that it splits the
true IPMI processing from the business logic.

Tested: Only ran unit-tests (added new ones).
Change-Id: I09d95d8be8fbe75648b3332af898336b00074c2f
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/handler_mock.hpp b/test/handler_mock.hpp
index a99f131..a92606a 100644
--- a/test/handler_mock.hpp
+++ b/test/handler_mock.hpp
@@ -17,6 +17,9 @@
 
     MOCK_CONST_METHOD0(getEthDetails, std::tuple<std::uint8_t, std::string>());
     MOCK_CONST_METHOD1(getRxPackets, std::int64_t(const std::string&));
+    MOCK_CONST_METHOD1(getCpldVersion,
+                       std::tuple<std::uint8_t, std::uint8_t, std::uint8_t,
+                                  std::uint8_t>(unsigned int));
 };
 
 } // namespace ipmi