Hi, Tilak,
Anyway, I do not think you can use SD/MMC module to access Nand flash, as you know that the NAND flash has I/O signals, ALE, WE, RE, CLE, CE... signals, which the MMC module can not provide.
But I think it is okay if you use GPIO to simulate the NAND flash, but I do not think there is any library to support the simulation.
The LPC1788 supports NAND flash via EMC module, pls refer to the link:
https://www.embeddedartists.com/products/lpc1788-oem/
Hope it can help you
BR
XiangJun rong