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/cs46xx/cs46xx_lib.c b/sound/pci/cs46xx/cs46xx_lib.c
index fb3abb2..8d74004 100644
--- a/sound/pci/cs46xx/cs46xx_lib.c
+++ b/sound/pci/cs46xx/cs46xx_lib.c
@@ -57,6 +57,7 @@
 #include <linux/module.h>
 #include <linux/firmware.h>
 #include <linux/vmalloc.h>
+#include <linux/io.h>
 
 #include <sound/core.h>
 #include <sound/control.h>
@@ -65,8 +66,6 @@
 #include <sound/pcm_params.h>
 #include "cs46xx.h"
 
-#include <asm/io.h>
-
 #include "cs46xx_lib.h"
 #include "dsp_spos.h"