i2c-gpio: Initialize adapter class

This is required to let hwmon drivers attach to the adapter.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

drivers/i2c/busses/i2c-gpio.c

@@ -140,6 +140,7 @@ static int __init i2c_gpio_probe(struct platform_device *pdev)
 	adap->owner = THIS_MODULE;
 	snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id);
 	adap->algo_data = bit_data;
+	adap->class = I2C_CLASS_HWMON;
 	adap->dev.parent = &pdev->dev;
 
 	/*