util/vgabios: build/warning fixes.

Signed-off-by: Luc Verhaegen <libv@skynet.be>
Acked-by: Stefan Reinauer <stepan@coresystems.de>

git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4312 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

util/vgabios/testbios.c

@@ -11,6 +11,7 @@
 #define warn(x) { perror(x);  }
 
 #include <x86emu.h>
+#include "helper_exec.h"
 #include "test.h"
 #include "pci-userspace.h"