Hi we are using the original N25Q128A and have tested the recommended replacement MT25QU128. These are on allocation and hard to get hold off. We are running at 1.8V.
All of the remaining recommend parts in
Are there any manufacturers of 1.8V FLASH parts in 8 pin SON packages that are known to work?
https://www.xilinx.com/support/answers/50991.html lists the flashes tested by Xilinx.
Usually the 1.8V equivalent should work.
You might need to do some minor modification in u-boot to include the JEDEC ID for the 1.8V flash.