Input: tm2-touchkey - use LEN_ON as boolean value instead of LED_FULL

Commit 4e552c8c ("leds: add LED_ON brightness as boolean value")
has introduced the LED_ON enumeration value that can be used
instead of LED_FULL which has more of a linear value.

Because the tm2-touchscreen doesn't have brightness levels, but
it's a simple on/off led, use LED_ON instead of LED_FULL.
Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Reviewed-by: Jaechul Lee <jcsing.lee@samsung.com>
Tested-by: Jaechul Lee <jcsing.lee@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/tm2-touchkey.c

@@ -213,7 +213,7 @@ static int tm2_touchkey_probe(struct i2c_client *client,
 	/* led device */
 	touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
 	touchkey->led_dev.brightness = LED_FULL;
-	touchkey->led_dev.max_brightness = LED_FULL;
+	touchkey->led_dev.max_brightness = LED_ON;
 	touchkey->led_dev.brightness_set = tm2_touchkey_led_brightness_set;
 
 	error = devm_led_classdev_register(&client->dev, &touchkey->led_dev);