ALSA: Include linux/io.h instead of asm/io.h

Nowadays it's recommended.  Replace all in a shot.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/als300.c b/sound/pci/als300.c
index bd01113..57e034f 100644
--- a/sound/pci/als300.c
+++ b/sound/pci/als300.c
@@ -37,8 +37,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/interrupt.h>
 #include <linux/slab.h>
-
-#include <asm/io.h>
+#include <linux/io.h>
 
 #include <sound/core.h>
 #include <sound/control.h>