Fan and power improvements

[jackpot51]

• Re-enable interpolation, which was found to be important when reviewing Thomas' improved fan curve #550
• Fix power.sh script, used for debugging fan curve: scripts: Fix ectool commands in power script #559
• Configurable power levels (PL1, PL2, and TCC) - potentially exposed via /sys/firmware/acpi/platform_profile
• Configurable fan curves (either with baked-in quiet, balanced, cool options or exposing point configuration to the OS)

[higher972]

As a lemp13-b user, I would be incredibly grateful for the "Configurable fan curves" option. Any task with a constant low/medium load causes the fan to repeatedly cut on and off, and can be rather distracting. Ideally, one curve could provide a constant low/medium fan speed in response to a constant low/medium load. (Or allow the easy configuration of such a curve.)

The current curve is fantastic for when the system is mostly idle. But the inability to manage fan noise in other cases (without recompiling the firmware) is the one thing that makes me hesitant to recommend the Lemur Pro to others.