The following error occurs:
m25p80 spi32766.0: unrecognized JEDEC id ba1810
xilinx_spi 40a10000.spi: at 0x40A10000 mapped to 0xf00e0000, irq=8
This was working on a 13.4 version of the core (failing in 14.1 and 14.2).
The JEDEC code appears to be 0xBA1810 instead of 0x20BA18.
The issue will be fixed in 14.3.