hw/nvram/xlnx-efuse: Do not expose as user-creatable

This device is part of SoC components thus can not
be created manually.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20250325224310.8785-10-philmd@linaro.org>

hw/nvram/xlnx-efuse.c

@@ -280,6 +280,8 @@ static void efuse_class_init(ObjectClass *klass, void *data)
 
     dc->realize = efuse_realize;
     device_class_set_props(dc, efuse_properties);
+    /* Reason: Part of Xilinx SoC */
+    dc->user_creatable = false;
 }
 
 static const TypeInfo efuse_info = {