Adapt sources to configurable config.h name
diff --git a/library/ssl_ciphersuites.c b/library/ssl_ciphersuites.c
index 25d192b..8018fe7 100644
--- a/library/ssl_ciphersuites.c
+++ b/library/ssl_ciphersuites.c
@@ -25,7 +25,11 @@
  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#if !defined(POLARSSL_CONFIG_FILE)
 #include "polarssl/config.h"
+#else
+#include POLARSSL_CONFIG_FILE
+#endif
 
 #if defined(POLARSSL_SSL_TLS_C)