hwmon: (w83773g) Fix build warning

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

drivers/hwmon/w83773g.c:47:34: warning:
	‘w83773_of_match’ defined but not used

Mark w83773_of_match as __maybe_unused to fix the problem.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/w83773g.c

@@ -44,7 +44,7 @@ static const struct i2c_device_id w83773_id[] = {
 
 MODULE_DEVICE_TABLE(i2c, w83773_id);
 
-static const struct of_device_id w83773_of_match[] = {
+static const struct of_device_id __maybe_unused w83773_of_match[] = {
 	{
 		.compatible = "nuvoton,w83773g"
 	},