kconfig: split menu.c out of parser.y

Compile menu.c as an independent compilation unit.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index 8b2108b..606ba8a 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -9,6 +9,7 @@
 #include <string.h>
 
 #include "lkc.h"
+#include "internal.h"
 
 static const char nohelp_text[] = "There is no help available for this option.";