ALSA: Fix invalid __exit in sound/mips/*.c

The remove callback has to be marked as __devexit, as the dynamic unbind
is possible.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/mips/hal2.c b/sound/mips/hal2.c
index c52691c..9a88cdf 100644
--- a/sound/mips/hal2.c
+++ b/sound/mips/hal2.c
@@ -915,7 +915,7 @@
 	return 0;
 }
 
-static int __exit hal2_remove(struct platform_device *pdev)
+static int __devexit hal2_remove(struct platform_device *pdev)
 {
 	struct snd_card *card = platform_get_drvdata(pdev);