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/debug.c b/src/northbridge/intel/i440bx/debug.c
index b2b9617..63b8e8f 100644
--- a/src/northbridge/intel/i440bx/debug.c
+++ b/src/northbridge/intel/i440bx/debug.c
@@ -2,8 +2,8 @@
 
 #include <console/console.h>
 #include <device/pci_ops.h>
+#include <device/smbus_host.h>
 #include <spd.h>
-#include <southbridge/intel/i82371eb/i82371eb.h>
 #include "raminit.h"
 
 void dump_spd_registers(void)