Porting the WICED DHCP server code will not be straightforward since that is tightly coupled with the hooks of WICED SDK.
I had earlier tried to clean up the DHCP Server code but did not really test it out. Nevertheless, I am attaching the same here for you to check with your application. You can just add this .c, .h files inside your application code folder and call start_dhcp_server from your main app. Let me know how this goes.
Disclaimer: This code snippet has not been tested or gone through standard Cypress review procedure.