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/isa/opl3sa2.c b/sound/isa/opl3sa2.c
index d7aff52..ae13363 100644
--- a/sound/isa/opl3sa2.c
+++ b/sound/isa/opl3sa2.c
@@ -26,6 +26,7 @@
 #include <linux/pm.h>
 #include <linux/pnp.h>
 #include <linux/module.h>
+#include <linux/io.h>
 #include <sound/core.h>
 #include <sound/wss.h>
 #include <sound/mpu401.h>
@@ -33,8 +34,6 @@
 #include <sound/initval.h>
 #include <sound/tlv.h>
 
-#include <asm/io.h>
-
 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
 MODULE_DESCRIPTION("Yamaha OPL3SA2+");
 MODULE_LICENSE("GPL");