hwmon: (nct6683) Display warning when enabling driver for unknown customer

Enabling the driver for devices with unknown customer ID is at least
somewhat risky, so add a warning to the kernel log.

Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/nct6683.c

···
 	default:
 		if (!force)
 			return -ENODEV;
+		dev_warn(dev, "Enabling support for unknown customer ID 0x%04x\n", data->customer_id);
+		break;
 	}
 
 	nct6683_init_device(data);