[coreboot] How to change the device id of a VBIOS

[Bao, Zheng]

Some of the VGA modules have almost same function and vgabios. The only
difference is the Device ID. I am wondering, if I got a Vgabios for
graphics card A, can I just change the device ID in the binary file to
fit the graphics B? Is there any checksum in the vgabios.bin? Is there a
tool to handle it?

Zheng