what is Configuration Device in Convert Programming Files?

I'm not sure which manufacturer the M25P64 flash you mentioned belongs to. Altera has recommended and verified flash devices from specific manufacturers—please refer to Table 4 in the linked document for details.

https://www.intel.com/content/www/us/en/support/programmable/support-resources/design-guidance/configuration-support.html

If your flash device is not listed there, you first need to confirm whether it can be used as a boot device for Cyclone devices. You can do this by checking parameters like dummy cycles, addressing, etc., as outlined in Table 4 for verified devices.

If you confirm that your flash is compatible, you can generate a new template in the Convert Programming Files tool by selecting "New Device".