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/include/sound/emu10k1.h b/include/sound/emu10k1.h
index 7f6ab6c..0de95cc 100644
--- a/include/sound/emu10k1.h
+++ b/include/sound/emu10k1.h
@@ -33,8 +33,8 @@
 #include <linux/interrupt.h>
 #include <linux/mutex.h>
 #include <linux/firmware.h>
+#include <linux/io.h>
 
-#include <asm/io.h>
 #include <uapi/sound/emu10k1.h>
 
 /* ------------------- DEFINES -------------------- */