Fix typos

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/include/mbedtls/build_info.h b/include/mbedtls/build_info.h
index fd61bca..0048cee 100644
--- a/include/mbedtls/build_info.h
+++ b/include/mbedtls/build_info.h
@@ -123,7 +123,7 @@
 
 /* The following blocks make it easier to disable all of TLS,
  * or of TLS 1.2 or 1.3 or DTLS, without having to manually disable all
- * key  and extensions related to them. */
+ * key exchanges, options and extensions related to them. */
 
 #if !defined(MBEDTLS_SSL_TLS_C)
 #undef MBEDTLS_SSL_CLI_C