Fix type used for capturing TLS ticket generation time

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/ssl_ticket.c b/library/ssl_ticket.c
index 28c4d3e..cdccf2e 100644
--- a/library/ssl_ticket.c
+++ b/library/ssl_ticket.c
@@ -79,7 +79,7 @@
 #endif
 
 #if defined(MBEDTLS_HAVE_TIME)
-    key->generation_time = (uint32_t) mbedtls_time( NULL );
+    key->generation_time = mbedtls_time( NULL );
 #endif
 
     if( ( ret = ctx->f_rng( ctx->p_rng, key->name, sizeof( key->name ) ) ) != 0 )
@@ -122,8 +122,8 @@
 #else
     if( ctx->ticket_lifetime != 0 )
     {
-        uint32_t current_time = (uint32_t) mbedtls_time( NULL );
-        uint32_t key_time = ctx->keys[ctx->active].generation_time;
+        mbedtls_time_t current_time = mbedtls_time( NULL );
+        mbedtls_time_t key_time = ctx->keys[ctx->active].generation_time;
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
         psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
@@ -204,7 +204,7 @@
     ctx->ticket_lifetime = lifetime;
     memcpy( key->name, name, TICKET_KEY_NAME_BYTES );
 #if defined(MBEDTLS_HAVE_TIME)
-    key->generation_time = (uint32_t) mbedtls_time( NULL );
+    key->generation_time = mbedtls_time( NULL );
 #endif
     return 0;
 }