platform-mc: Add sensor manager

Added sensor_manager class. The sensor_manager class manages the timing
of sensor polling.

tested: Verified on ast2600 EVB which is connected to a PLDM device
over I2C. bmcweb can display the state of numeric sensor.

Signed-off-by: Gilbert Chen <gilbert.chen@arm.com>
Signed-off-by: Thu Nguyen <thu@os.amperecomputing.com>
Change-Id: I4257f823ea26d7fdb322cc82d847e94db056258c
diff --git a/platform-mc/test/mock_sensor_manager.hpp b/platform-mc/test/mock_sensor_manager.hpp
new file mode 100644
index 0000000..a52e4ea
--- /dev/null
+++ b/platform-mc/test/mock_sensor_manager.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include "platform-mc/sensor_manager.hpp"
+
+#include <gmock/gmock.h>
+
+namespace pldm
+{
+namespace platform_mc
+{
+
+class MockSensorManager : public SensorManager
+{
+  public:
+    MockSensorManager(sdeventplus::Event& event,
+                      TerminusManager& terminusManager,
+                      TerminiMapper& termini) :
+        SensorManager(event, terminusManager, termini) {};
+
+    MOCK_METHOD(void, doSensorPolling, (pldm_tid_t tid), (override));
+};
+
+} // namespace platform_mc
+} // namespace pldm