The generate-by-PCI-device-ID rules (bin/pci_VVVV_DDDD.rom) are generally
used for building actual ROM images to be burned, and the burning
utilities generally run under some DOS variant.  Change the filename from
pci_VVVV_DDDD.rom to VVVVDDDD.rom so that it is compatible with the DOS
8.3-character filename limit.

needing to know the gPXE internal ROM name.