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/maestro3.c b/sound/pci/maestro3.c
index 18a60be..9be6609 100644
--- a/sound/pci/maestro3.c
+++ b/sound/pci/maestro3.c
@@ -31,7 +31,7 @@
 #define CARD_NAME "ESS Maestro3/Allegro/Canyon3D-2"
 #define DRIVER_NAME "Maestro3"
 
-#include <asm/io.h>
+#include <linux/io.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/init.h>