ASoC: ac97: add MODULE_ALIAS for the platform driver

So that modprobe can load the driver automatically when the platform device
appears.

Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/ac97.c

@@ -162,3 +162,4 @@ module_exit(ac97_exit);
 MODULE_DESCRIPTION("Soc Generic AC97 driver");
 MODULE_AUTHOR("Liam Girdwood");
 MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ac97-codec");