Add ifdef for selftest in header file
See https://github.com/ARMmbed/mbedtls/pull/975
diff --git a/include/mbedtls/chachapoly.h b/include/mbedtls/chachapoly.h
index ae786e0..249dba1 100644
--- a/include/mbedtls/chachapoly.h
+++ b/include/mbedtls/chachapoly.h
@@ -311,6 +311,7 @@
const unsigned char *input,
unsigned char *output );
+#if defined(MBEDTLS_SELF_TEST)
/**
* \brief The ChaCha20-Poly1305 checkup routine.
*
@@ -318,6 +319,7 @@
* \return \c 1 on failure.
*/
int mbedtls_chachapoly_self_test( int verbose );
+#endif /* MBEDTLS_SELF_TEST */
#ifdef __cplusplus
}