hwmon: (w83773g) Add documentation

Kernel driver w83773g

====================

Supported chips:

  * Nuvoton W83773G

    Prefix: 'w83773g'

    Addresses scanned: I2C 0x4c and 0x4d

    Datasheet: https://www.nuvoton.com/resource-files/W83773G_SG_DatasheetV1_2.pdf

Authors:

	Lei YU <mine260309@gmail.com>

Description

-----------

This driver implements support for Nuvoton W83773G temperature sensor

chip. This chip implements one local and two remote sensors.

The chip also features offsets for the two remote sensors which get added to

the input readings. The chip does all the scaling by itself and the driver

therefore reports true temperatures that don't need any user-space adjustments.

Temperature is measured in degrees Celsius.

The chip is wired over I2C/SMBus and specified over a temperature

range of -40 to +125 degrees Celsius (for local sensor) and -40 to +127

degrees Celsius (for remote sensors).

Resolution for both the local and remote channels is 0.125 degree C.

The chip supports only temperature measurement. The driver exports

the temperature values via the following sysfs files:

temp[1-3]_input

temp[2-3]_fault

temp[2-3]_offset

update_interval