add handler logic to handle i2c pcie commands

Add handler logic to manage the i2c pcie commands and their
corresponding data structure.

Tested: Only ran unit-tests (added new ones).
Change-Id: Ibd65d6745202dbf6bd67cd2cb480914ca6ae4ed1
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/handler_mock.hpp b/test/handler_mock.hpp
index 6394f68..b97cce3 100644
--- a/test/handler_mock.hpp
+++ b/test/handler_mock.hpp
@@ -22,6 +22,10 @@
                                   std::uint8_t>(unsigned int));
     MOCK_CONST_METHOD1(psuResetDelay, void(std::uint32_t));
     MOCK_METHOD2(getEntityName, std::string(std::uint8_t, std::uint8_t));
+    MOCK_METHOD0(buildI2cPcieMapping, void());
+    MOCK_CONST_METHOD0(getI2cPcieMappingSize, size_t());
+    MOCK_CONST_METHOD1(getI2cEntry,
+                       std::tuple<std::uint32_t, std::string>(unsigned int));
 };
 
 } // namespace ipmi