adt7473: minor documentation update

Add a sentence about when fan speed increases to maximum.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/hwmon/adt7473

@@ -69,7 +69,8 @@ point2: Set the pwm speed at a higher temperature bound.
 
 The ADT7473 will scale the pwm between the lower and higher pwm speed when
 the temperature is between the two temperature boundaries.  PWM values range
-from 0 (off) to 255 (full speed).
+from 0 (off) to 255 (full speed).  Fan speed will be set to maximum when the
+temperature sensor associated with the PWM control exceeds temp#_max.
 
 Notes
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