The cleanup action for the FuVliUsbhubPdDevice is correct, but was not
conditionalized in the composite cleanup, which meant we would reboot twice
for a normal USB hub update.
Move the parent reboot into the right place, although this does mean we might
reboot twice in the rare event of scheduing a FuVliUsbhubPdDevice *and*
FuVliUsbhubDevice update in the same transaction -- but resetting the device
state between updates is arguably correct anyway...
I misunderstood the original specification, and it seems even USB-hub-less
devices have the same header location as their "write-through" counterparts.
If we say that the version format should be the same for the `version_lowest`
and the `version_bootloader` then it does not always make sense to set it at
the same time.
Moving the `version_format` to a standalone first-class property also means it
can be typically be set in the custom device `_init()` function, which means we
don't need to worry about *changing* ther version format as set by the USB and
UDev superclass helpers.
To implement the SPI commands, objects can derive from FuVliDevice and
implement the new vfuncs. This allows us to override the implementation for
minor API changes.
