ASoC: mxs: Add appropriate MODULE_ALIAS()

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/mxs/mxs-pcm.c b/sound/soc/mxs/mxs-pcm.c
index 8646913..f39d7dd 100644
--- a/sound/soc/mxs/mxs-pcm.c
+++ b/sound/soc/mxs/mxs-pcm.c
@@ -359,3 +359,4 @@
 module_exit(snd_mxs_pcm_exit);
 
 MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mxs-pcm-audio");