MCUTempSensor: Fix PDB temparature reading show nan

Actually, i2c_smbus_read_word_data() return value is
not mapped correctly. So, fixed i2c_smbus_read_word_data()
return type to signed int32 from int16_t.

Tested: Verified PDB temperature reading is getting
reported correctly via D-Bus.

Change-Id: I0a00d5b20c0576abe5635e96b3afadc572241f0a
Signed-off-by: Saitwal, Meghan <meghan.saitwal@intel.com>
diff --git a/src/MCUTempSensor.hpp b/src/MCUTempSensor.hpp
index 639e24e..4007546 100644
--- a/src/MCUTempSensor.hpp
+++ b/src/MCUTempSensor.hpp
@@ -28,7 +28,7 @@
     uint8_t tempReg;
 
   private:
-    int getMCURegsInfoWord(uint8_t regs, int16_t* pu16data) const;
+    int getMCURegsInfoWord(uint8_t regs, int32_t* pu32data) const;
     sdbusplus::asio::object_server& objectServer;
     boost::asio::steady_timer waitTimer;
 };