Temporarily include private symbols in sample programs

Signed-off-by: Ben Taylor <ben.taylor@linaro.org>
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 40304dd..b31dc92 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -6,6 +6,9 @@
  */
 
 #define MBEDTLS_ALLOW_PRIVATE_ACCESS
+#define MBEDTLS_DECLARE_PRIVATE_IDENTIFIERS
+
+#include "mbedtls/private/pk_private.h"
 
 #include "ssl_test_lib.h"