Include byteorder.h for the definition of ntohl in romstage.c

A fix to eliminate warnings when building romstage files with ChromeOS
compilers

Change-Id: Ia5d7bbdde3aa3439fd493f5795f2cc2bf4c4c187
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: http://review.coreboot.org/2781
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/mainboard/samsung/stumpy/romstage.c b/src/mainboard/samsung/stumpy/romstage.c
index 5fecfef..1fad949 100644
--- a/src/mainboard/samsung/stumpy/romstage.c
+++ b/src/mainboard/samsung/stumpy/romstage.c
@@ -22,6 +22,7 @@
 #include <string.h>
 #include <lib.h>
 #include <timestamp.h>
+#include <arch/byteorder.h>
 #include <arch/io.h>
 #include <arch/romcc_io.h>
 #include <device/pci_def.h>