backlight: atmel-pwm-bl: fix module autoload

Add missing module alias which is needed for module autoloading.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/atmel-pwm-bl.c

@@ -229,3 +229,4 @@ module_platform_driver(atmel_pwm_bl_driver);
 MODULE_AUTHOR("Hans-Christian egtvedt <hans-christian.egtvedt@atmel.com>");
 MODULE_DESCRIPTION("Atmel PWM backlight driver");
 MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:atmel-pwm-bl");