tls13: srv: Fix guards of _is_psk_(ephemeral_)available

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 5c5ef5d..92e8add 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -172,12 +172,12 @@
 #define SSL_TLS1_3_PSK_IDENTITY_MATCH_BUT_PSK_NOT_USABLE 1
 #define SSL_TLS1_3_PSK_IDENTITY_MATCH 0
 
-#if defined(MBEDTLS_SSL_SESSION_TICKETS)
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_key_exchange_is_psk_available(mbedtls_ssl_context *ssl);
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_key_exchange_is_psk_ephemeral_available(mbedtls_ssl_context *ssl);
 
+#if defined(MBEDTLS_SSL_SESSION_TICKETS)
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_offered_psks_check_identity_match_ticket(
     mbedtls_ssl_context *ssl,