sysutils/bsdsensors: New port: utility to read sensor data and control fan speed

Here's a new port, which provides a simple utility to read sensor data
and control fan speed. Specifically, it supports a few Nuvoton embedded
controllers, which are widely used in consumer-grade motherboards.

The utility can

• read temp sensor
• read voltage sensor
• read fan speed
• read fan curve and control information
• write fan curve and control params

It's released under BSD 3-clause.

https://github.com/HenryHu/bsdsensors

PR: 284144