Move the declaration of query_config() to a dedicated header file

Declaring query_config() belongs with the query_config program, not in
ssl_test_lib.h, so move the declaration to a new header file
query_config.h.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/programs/ssl/ssl_test_lib.h b/programs/ssl/ssl_test_lib.h
index 666e694..031c872 100644
--- a/programs/ssl/ssl_test_lib.h
+++ b/programs/ssl/ssl_test_lib.h
@@ -83,20 +83,7 @@
 
 #include <test/helpers.h>
 
-/** Check whether a given configuration symbol is enabled.
- *
- * \param config    The symbol to query (e.g. "MBEDTLS_RSA_C").
- * \return          \c 0 if the symbol was defined at compile time
- *                  (in MBEDTLS_CONFIG_FILE or config.h),
- *                  \c 1 otherwise.
- *
- * \note            This function is defined in `programs/test/query_config.c`
- *                  which is automatically generated by
- *                  `scripts/generate_query_config.pl`.
- */
-int query_config( const char *config );
-
-
+#include "../test/query_config.h"
 
 #if defined(MBEDTLS_SSL_EXPORT_KEYS)