defined:
define match functions to take a struct cfdata * as their second
argument, config_search() to take a struct cfdata * as its second
argument, and config_{root,}search() to return struct cfdata *.
remove 'cd_indirect' cfdriver element.
remove config_scan().
remove config_make_softc() as a seperate function, reintegrating
its functionality into config_attach().
Ports will define __BROKEN_INDIRECT_CONFIG until their drivers prototypes
are updated to work with the new definitions, and until it is sure that
their indirect-config drivers do not assume that they have a softc
in their match routine.