hwmon: (lm85) Fix build warning

The following build warning is seen if CONFIG_OF is disabled.

drivers/hwmon/lm85.c:1645:34: warning:
	‘lm85_of_match’ defined but not used

Mark lm85_of_match as __maybe_unused to ix the problem.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>