tls13_only: guard ssl_{cli,srv}.c with TLS1_2

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 9104a59..e7fc8ea 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -89,14 +89,12 @@
 /* Determine maximum supported version */
 #define MBEDTLS_SSL_MAX_MAJOR_VERSION           MBEDTLS_SSL_MAJOR_VERSION_3
 
-#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
-#define MBEDTLS_SSL_MAX_MINOR_VERSION           MBEDTLS_SSL_MINOR_VERSION_4
-#elif defined(MBEDTLS_SSL_PROTO_TLS1_2)
+#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
 #define MBEDTLS_SSL_MAX_MINOR_VERSION           MBEDTLS_SSL_MINOR_VERSION_3
+#elif defined(MBEDTLS_SSL_PROTO_TLS1_3)
+#define MBEDTLS_SSL_MAX_MINOR_VERSION           MBEDTLS_SSL_MINOR_VERSION_4
 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
 
-
-
 /* Shorthand for restartable ECC */
 #if defined(MBEDTLS_ECP_RESTARTABLE) && \
     defined(MBEDTLS_SSL_CLI_C) && \