hwmon: (lm90) Fix build warning

If CONFIG_OF is not enabled, the following build warning is observed.

drivers/hwmon/lm90.c:239:34: warning:
	‘lm90_of_match’ defined but not used

Mark lm90_of_match as __maybe_unused to fix the problem.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/lm90.c

@@ -236,7 +236,7 @@ static const struct i2c_device_id lm90_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, lm90_id);
 
-static const struct of_device_id lm90_of_match[] = {
+static const struct of_device_id __maybe_unused lm90_of_match[] = {
 	{
 		.compatible = "adi,adm1032",
 		.data = (void *)adm1032