device/smbus_host: Declare common early SMBus prototypes

Change-Id: I1157cf391178a27db437d1d08ef5cb9333e976d0
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38233
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/northbridge/intel/i440bx/raminit.c b/src/northbridge/intel/i440bx/raminit.c
index 1910813..e5d377e 100644
--- a/src/northbridge/intel/i440bx/raminit.c
+++ b/src/northbridge/intel/i440bx/raminit.c
@@ -6,13 +6,12 @@
 #include <device/mmio.h>
 #include <device/pci_ops.h>
 #include <device/pci_def.h>
+#include <device/smbus_host.h>
 #include <console/console.h>
 #include <timestamp.h>
 #include "i440bx.h"
 #include "raminit.h"
 
-#include <southbridge/intel/i82371eb/i82371eb.h>
-
 /*
  * Macros and definitions
  */