hwmon: (yogafan) Add support for Lenovo Yoga/Legion fan monitoring

hwmon: (yogafan) Add support for Lenovo Yoga/Legion fan monitoring

This driver provides fan speed monitoring for Lenovo Yoga, Legion, and
IdeaPad laptops by interfacing with the Embedded Controller (EC) via ACPI.

To address low-resolution sampling in Lenovo EC firmware, a Rate-Limited
Lag (RLLag) filter is implemented. The filter ensures a consistent physical
curve regardless of userspace polling frequency.

Hardware identification is performed via DMI-based quirk tables, which
map specific ACPI object paths and register widths (8-bit vs 16-bit)
deterministically.

Signed-off-by: Sergio Melas <sergiomelas@gmail.com>
Link: https://lore.kernel.org/r/20260327221602.18832-1-sergiomelas@gmail.com
[groeck: Dropped double empty line in Kconfig]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>