Add dummy tls1.3 handshake dispatch functions

Base on version config, `handshack_{clinet,server}_step`
will call different step function. TLS1.3 features will
be gradully added base on it.

And a new test cases is added to make sure it reports
`feature is not available`.

Change-Id: I4f0e36cb610f5aa59f97910fb8204bfbf2825949
Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index ecead57..01265ae 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -8501,6 +8501,15 @@
             -s "Hybrid TLS 1.2 + TLS 1.3 configurations are not yet supported" \
             -c "Hybrid TLS 1.2 + TLS 1.3 configurations are not yet supported"
 
+requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
+requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL
+run_test    "TLS1.3: handshake dispatch test: tls1_3 only" \
+            "$P_SRV min_version=tls1_3 max_version=tls1_3" \
+            "$P_CLI min_version=tls1_3 max_version=tls1_3" \
+            1 \
+            -s "SSL - The requested feature is not available" \
+            -c "SSL - The requested feature is not available"
+
 # Test heap memory usage after handshake
 requires_config_enabled MBEDTLS_MEMORY_DEBUG
 requires_config_enabled MBEDTLS_MEMORY_BUFFER_ALLOC_C