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/echoaudio/indigoio.c b/sound/pci/echoaudio/indigoio.c
index 405a3f2..f7618ed 100644
--- a/sound/pci/echoaudio/indigoio.c
+++ b/sound/pci/echoaudio/indigoio.c
@@ -46,6 +46,7 @@
 #include <linux/module.h>
 #include <linux/firmware.h>
 #include <linux/slab.h>
+#include <linux/io.h>
 #include <sound/core.h>
 #include <sound/info.h>
 #include <sound/control.h>
@@ -54,7 +55,6 @@
 #include <sound/pcm_params.h>
 #include <sound/asoundef.h>
 #include <sound/initval.h>
-#include <asm/io.h>
 #include <linux/atomic.h>
 #include "echoaudio.h"