ABI: hwmon: Document "label" sysfs attribute

Add the "label" sysfs attribute, which can contain a descriptive label
that allows to uniquely identify a device within the system.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220110182256.30763-2-paul@crapouillou.netSigned-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/ABI/testing/sysfs-class-hwmon

@@ -9,6 +9,14 @@ Description:
 
 		RO
 
+What:		/sys/class/hwmon/hwmonX/label
+Description:
+		A descriptive label that allows to uniquely identify a
+		device within the system.
+		The contents of the label are free-form.
+
+		RO
+
 What:		/sys/class/hwmon/hwmonX/update_interval
 Description:
 		The interval at which the chip will update readings.

Documentation/hwmon/sysfs-interface.rst

@@ -99,6 +99,10 @@ Global attributes
 `name`
 		The chip name.
 
+`label`
+		A descriptive label that allows to uniquely identify a device
+		within the system.
+
 `update_interval`
 		The interval at which the chip will update readings.