nvidia-gpu: add thresholds support to TLimit

This patch introduces support for retrieving GPU TLimit thresholds
directly from the GPU device. TLimit Temperature represents the
difference in degrees

nvidia-gpu: add thresholds support to TLimit

This patch introduces support for retrieving GPU TLimit thresholds
directly from the GPU device. TLimit Temperature represents the
difference in degrees Celsius between the current GPU temperature and
the initial throttle threshold. The patch also enables the extraction of
three critical throttle thresholds — Warning Low, Critical Low, and Hard
Shutdown Low — from the GPU hardware.

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://10.137.203.137/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_0_TEMP_1
{
"@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_0_TEMP_1",
"@odata.type": "#Sensor.v1_2_0.Sensor",
"Id": "temperature_NVIDIA_GB200_GPU_0_TEMP_1",
"Name": "NVIDIA GB200 GPU 0 TEMP 1",
"Reading": 57.3984375,
"ReadingRangeMax": 127.0,
"ReadingRangeMin": -128.0,
"ReadingType": "Temperature",
"ReadingUnits": "Cel",
"Status": {
"Health": "OK",
"State": "Enabled"
},
"Thresholds": {
"LowerCaution": {
"Reading": 0.0
},
"LowerCritical": {
"Reading": 0.0
},
"LowerFatal": {
"Reading": 0.0
}
}
}%
```

Change-Id: I6f2ff2652ce9246287f9bd63c4297d9ad3229963
Signed-off-by: Harshit Aghera <haghera@nvidia.com>

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