x200/romstage: Add missing include.

Change-Id: I47aa8619ba1e1939707ec654ffb54cae316929cf
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/7684
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Tested-by: build bot (Jenkins)

src/mainboard/lenovo/x200/romstage.c

@@ -33,6 +33,7 @@
 #include <console/console.h>
 #include <southbridge/intel/i82801ix/i82801ix.h>
 #include <northbridge/intel/gm45/gm45.h>
+#include <cpu/intel/romstage.h>
 
 #define LPC_DEV PCI_DEV(0, 0x1f, 0)
 #define MCH_DEV PCI_DEV(0, 0, 0)