Add comments to fix mini format issue

Signed-off-by: Xiaokang Qian <xiaokang.qian@arm.com>
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 02685e1..5294ec2 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -813,9 +813,9 @@
 
 typedef uint8_t mbedtls_ssl_tls13_ticket_flags;
 #define MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_PSK_RESUMPTION \
-    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK
+    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK /* 1U << 0 */
 #define MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_PSK_EPHEMERAL_RESUMPTION \
-    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL
+    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL /* 1U << 2 */
 #define MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_EARLY_DATA \
     MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_PSK_EPHEMERAL_RESUMPTION << 1