ABI: sysfs-class-hwmon: add a description for tempY_crit_alarm

Such ABI symbol is currently not described. Document it.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/a14f98e1b23ea14cf14da3c3169955343ec28bbe.1632994837.git.mchehab+huawei@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/ABI/testing/sysfs-class-hwmon

@@ -410,6 +410,20 @@ Description:
 
 		RW
 
+What:		/sys/class/hwmon/hwmonX/tempY_crit_alarm
+Description:
+		Critical high temperature alarm flag.
+
+		- 0: OK
+		- 1: temperature has reached tempY_crit
+
+		RW
+
+		Contrary to regular alarm flags which clear themselves
+		automatically when read, this one sticks until cleared by
+		the user. This is done by writing 0 to the file. Writing
+		other values is unsupported.
+
 What:		/sys/class/hwmon/hwmonX/tempY_crit_hyst
 Description:
 		Temperature hysteresis value for critical limit.