Documentation rewording

Signed-off-by: TRodziewicz <tomasz.rodziewicz@mobica.com>
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 74b8222..4a98c5d 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -1013,8 +1013,7 @@
 /**
  * \def MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES
  *
- * Do not add default entropy sources. These are the platform specific
- * poll function.
+ * Do not add default entropy sources in mbedtls_entropy_init().
  *
  * This is useful to have more control over the added entropy sources in an
  * application.