ssl_server2: support ticket_aead only when CIPHER_C is defined

Cipher parsing requires mbedtls_cipher_info_from_string() which
depends on CIPHER_C.

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index c99703d..ccdabe4 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -283,6 +283,7 @@
 #else
 #define USAGE_PSK ""
 #endif /* MBEDTLS_SSL_HANDSHAKE_WITH_PSK_ENABLED */
+
 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
 #define USAGE_CA_CALLBACK                       \
     "   ca_callback=%%d       default: 0 (disabled)\n"      \
@@ -290,13 +291,21 @@
 #else
 #define USAGE_CA_CALLBACK ""
 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
+
 #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_TICKET_C)
+#if defined(MBEDTLS_CIPHER_C)
 #define USAGE_TICKETS                                       \
     "    tickets=%%d          default: 1 (enabled)\n"       \
     "    ticket_rotate=%%d    default: 0 (disabled)\n"      \
     "    ticket_timeout=%%d   default: 86400 (one day)\n"   \
     "    ticket_aead=%%s      default: \"AES-256-GCM\"\n"
-#else
+#else /* MBEDTLS_CIPHER_C */
+#define USAGE_TICKETS                                       \
+    "    tickets=%%d          default: 1 (enabled)\n"       \
+    "    ticket_rotate=%%d    default: 0 (disabled)\n"      \
+    "    ticket_timeout=%%d   default: 86400 (one day)\n"
+#endif /* MBEDTLS_CIPHER_C */
+#else /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_TICKET_C */
 #define USAGE_TICKETS ""
 #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_TICKET_C */
 
@@ -2146,14 +2155,18 @@
             if (opt.ticket_timeout < 0) {
                 goto usage;
             }
-        } else if (strcmp(p, "ticket_aead") == 0) {
+        } else
+#if defined(MBEDTLS_CIPHER_C)
+        if (strcmp(p, "ticket_aead") == 0) {
             const mbedtls_cipher_info_t *ci = mbedtls_cipher_info_from_string(q);
 
             if (ci == NULL) {
                 goto usage;
             }
             opt.ticket_aead = mbedtls_cipher_info_get_type(ci);
-        } else if (strcmp(p, "cache_max") == 0) {
+        } else
+#endif
+        if (strcmp(p, "cache_max") == 0) {
             opt.cache_max = atoi(q);
             if (opt.cache_max < 0) {
                 goto usage;