Update tlsDefaults doc to include cipher suites support (#2974)

Signed-off-by: Faseela K <faseela.k@est.tech>

Author: kfaseela

mesh/v1alpha1/config.pb.go

@@ -1170,7 +1170,7 @@ message MeshConfig {
   TLSConfig mesh_mTLS = 63;
   //
   // Configuration of TLS for all traffic except for ISTIO_MUTUAL mode.
-  // Currently, this supports configuration of ecdh_curves only.
+  // Currently, this supports configuration of ecdh_curves and cipher_suites only.
   // For ISTIO_MUTUAL TLS settings, use meshMTLS configuration.
   TLSConfig tls_defaults = 64;