Update/add SCM sensors and thresholds

[pawagh1]

This update refreshes the SCM section of sensor_service.json so it matches the latest threshold guidance and exposes the additional telemetry that the platform now reports.

Key highlights of this update:

Threshold Definition Updates:

• Refreshed upperCriticalVal and lowerCriticalVal settings for all SCM voltages and temperatures.
• Introduced maxAlarmVal and minAlarmVal where the new guidance specifies warning bands, improving early alarm coverage.

Additional Sensors:

• Added SCM_Vp1P0_PCIE4, SCM_I_VP1P05_CPU, and SCM_I_VP1P8_VCCIN so the service can monitor the new power rails and currents delivered by the SCM regulators.

No other fields (slotPath, sysfsPath, pmUnitName, type) were modified; only the thresholds and the new sensor entries were updated.

Test Plan:

• Confirm the sensor_service loads the updated JSON without validation errors.
• Verify each SCM sensor reports values inside the refreshed threshold ranges on hardware.
• Spot-check that the newly added sensors emit readings and appear in downstream monitoring dashboards.