arch/io.h: Separate MMIO and PNP ops

Change-Id: Ie32f1d43168c277be46cdbd7fbfa2445d9899689
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/31699
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/include/device/mmio.h

@@ -15,7 +15,7 @@
 #ifndef __DEVICE_MMIO_H__
 #define __DEVICE_MMIO_H__
 
-/* FIXME: We only want the volatile MMIO ops. */
-#include <arch/io.h>
+#include <arch/mmio.h>
+#include <endian.h>
 
 #endif