device/mmio.h: Add include file for MMIO ops

MMIO operations are arch-agnostic so the include
path should not be arch/.

Change-Id: I0fd70f5aeca02e98e96b980c3aca0819f5c44b98
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/31691
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/southbridge/amd/agesa/hudson/smi.h b/src/southbridge/amd/agesa/hudson/smi.h
index b67aec3..d1594f3 100644
--- a/src/southbridge/amd/agesa/hudson/smi.h
+++ b/src/southbridge/amd/agesa/hudson/smi.h
@@ -21,7 +21,7 @@
 #ifndef _SOUTHBRIDGE_AMD_AGESA_HUDSON_SMI_H
 #define _SOUTHBRIDGE_AMD_AGESA_HUDSON_SMI_H
 
-#include <arch/io.h>
+#include <device/mmio.h>
 
 /* ACPI_MMIO_BASE + 0x200 -- leave this string here so grep catches it.
  * This is defined by AGESA, but we dpn't include AGESA headers to avoid