i2c: i2c-at91: deprecate class based instantiation

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NLudovic Desroches <ludovic.desroches@atmel.com>

drivers/i2c/busses/i2c-at91.c

@@ -762,7 +762,7 @@ static int at91_twi_probe(struct platform_device *pdev)
 	snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
 	i2c_set_adapdata(&dev->adapter, dev);
 	dev->adapter.owner = THIS_MODULE;
-	dev->adapter.class = I2C_CLASS_HWMON;
+	dev->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_DEPRECATED;
 	dev->adapter.algo = &at91_twi_algorithm;
 	dev->adapter.dev.parent = dev->dev;
 	dev->adapter.nr = pdev->id;