This fixes the warning that's present for all VT8235 southbridges:
... Enabling flash write on VT8235...tried to set 0x4 to 0x14 on VT8235 failed (WARNING ONLY) ...
It's bourne from misinterpreting the return value of pci_write_byte, which peculiarly returns 1 for success.
Luc Verhaegen.