hwmon: (lm90) Fix update interval information in driver documentation

The lm90 driver's attribute update interval is configurable.
Reflect this information in the driver documentation.

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Documentation/hwmon/lm90

@@ -205,9 +205,9 @@ are exported, one for each channel, but these values are of course linked.
 Only the local hysteresis can be set from user-space, and the same delta
 applies to the remote hysteresis.
 
-The lm90 driver will not update its values more frequently than every
-other second; reading them more often will do no harm, but will return
-'old' values.
+The lm90 driver will not update its values more frequently than configured with
+the update_interval attribute; reading them more often will do no harm, but will
+return 'old' values.
 
 SMBus Alert Support
 -------------------