Add exported libsudo_util functions to util.exp and mark in headers

using __dso_public.

plugins/sudoers/toke.c

@@ -1997,11 +1997,6 @@ char *yytext;
 #  include <ndir.h>
 # endif
 #endif
-#ifdef HAVE_SHA224UPDATE
-# include <sha2.h>
-#else
-# include "compat/sha2.h"
-#endif
 #include <errno.h>
 #include <ctype.h>
 #include "sudoers.h"
@@ -2011,6 +2006,12 @@ char *yytext;
 #include "lbuf.h"
 #include "secure_path.h"
 
+#ifdef HAVE_SHA224UPDATE
+# include <sha2.h>
+#else
+# include "compat/sha2.h"
+#endif
+
 int sudolineno;			/* current sudoers line number. */
 int last_token;			/* last token that was parsed. */
 char *sudoers;			/* sudoers file being parsed. */