Fix type used for capturing TLS ticket generation time

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/include/mbedtls/ssl_ticket.h b/include/mbedtls/ssl_ticket.h
index 98fd287..fc86542 100644
--- a/include/mbedtls/ssl_ticket.h
+++ b/include/mbedtls/ssl_ticket.h
@@ -33,6 +33,7 @@
 
 #include "mbedtls/ssl.h"
 #include "mbedtls/cipher.h"
+#include "mbedtls/platform_time.h"
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
 #include "psa/crypto.h"
@@ -56,7 +57,7 @@
 {
     unsigned char MBEDTLS_PRIVATE(name)[MBEDTLS_SSL_TICKET_KEY_NAME_BYTES];
                                                      /*!< random key identifier              */
-    uint32_t MBEDTLS_PRIVATE(generation_time);       /*!< key generation timestamp (seconds) */
+    mbedtls_time_t MBEDTLS_PRIVATE(generation_time); /*!< key generation timestamp (seconds) */
 #if !defined(MBEDTLS_USE_PSA_CRYPTO)
     mbedtls_cipher_context_t MBEDTLS_PRIVATE(ctx);   /*!< context for auth enc/decryption    */
 #else