the quirk that disables tagged queueing for those drives.
Also, silence a warning by disabling xpt_for_all_targets() and
xpt_for_all_periphs(). These two functions are not currently used, but
they should not be removed. They're part of a set of functions that
provide a way to execute a function for every {bus,target,device,periph} in
the system.
If anyone needs to use either function in the future, they can be
un-#ifdefed.