definitions for more than one device (usually differentiated by
the PCI subvendor/subdevice ID). Each device also has its own tree
of registry keys. In some cases, each device has the same keys, but
sometimes each device has a unique tree but with overlap. Originally,
I just had ndiscvt(8) dump out all the keys it could find, and we
would try to apply them to every device we could find. Now, each key
has an index number that matches it to a device in the device ID list.
This lets us create just the keys that apply to a particular device.
I also added an extra field to the device list to hold the subvendor
and subdevice ID.
Some devices are generic, i.e. there is no subsystem definition. If
we have a device that doesn't match a specific subsystem value and
we have a generic entry, we use the generic entry.
