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>

sound/isa/sb/emu8000.c

@@ -26,10 +26,10 @@
 #include <linux/ioport.h>
 #include <linux/export.h>
 #include <linux/delay.h>
+#include <linux/io.h>
 #include <sound/core.h>
 #include <sound/emu8000.h>
 #include <sound/emu8000_reg.h>
-#include <asm/io.h>
 #include <asm/uaccess.h>
 #include <linux/init.h>
 #include <sound/control.h>