nvidia-gpu: add SMA Temperature Sensor

Add support for device type SMA (System Management Agent) and its
temperature sensor. It is typically an MCU device.

Tested: Build an image for gb200nvl-obmc machine with the following
patches cherry picked. This patches are needed to enable the mctp stack.

https://gerrit.openbmc.org/c/openbmc/openbmc/+/79422

```
$ curl -s -k -u 'root:0penBmc' https://10.137.203.193/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_SMA_255_TEMP_0
{
  "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_SMA_255_TEMP_0",
  "@odata.type": "#Sensor.v1_2_0.Sensor",
  "Id": "temperature_NVIDIA_GB200_GPU_SMA_255_TEMP_0",
  "Name": "NVIDIA GB200 GPU SMA 255 TEMP 0",
  "Reading": 34.0,
  "ReadingRangeMax": 127.0,
  "ReadingRangeMin": -128.0,
  "ReadingType": "Temperature",
  "ReadingUnits": "Cel",
  "Status": {
    "Health": "OK",
    "State": "Enabled"
  }
}%
```

Change-Id: I560864758036a5b6ea6c1745145736c7bfa0a1c5
Signed-off-by: Harshit Aghera <haghera@nvidia.com>
diff --git a/src/nvidia-gpu/NvidiaDeviceDiscovery.hpp b/src/nvidia-gpu/NvidiaDeviceDiscovery.hpp
index 86211a9..8b73453 100644
--- a/src/nvidia-gpu/NvidiaDeviceDiscovery.hpp
+++ b/src/nvidia-gpu/NvidiaDeviceDiscovery.hpp
@@ -28,15 +28,20 @@
 };
 
 class GpuDevice;
+class SmaDevice;
 
 void createSensors(
     boost::asio::io_context& io, sdbusplus::asio::object_server& objectServer,
     boost::container::flat_map<std::string, std::shared_ptr<GpuDevice>>&
         gpuDevices,
+    boost::container::flat_map<std::string, std::shared_ptr<SmaDevice>>&
+        smaDevices,
     const std::shared_ptr<sdbusplus::asio::connection>& dbusConnection,
     mctp::MctpRequester& mctpRequester);
 
 void interfaceRemoved(
     sdbusplus::message_t& message,
     boost::container::flat_map<std::string, std::shared_ptr<GpuDevice>>&
-        gpuDevices);
+        gpuDevices,
+    boost::container::flat_map<std::string, std::shared_ptr<SmaDevice>>&
+        smaDevices);