on indirect-config busses a (permanent) softc that they could share
between 'match' and 'attach' routines:
Define __BROKEN_INDIRECT_CONFIG so that old autoconfiguration
interfaces are used, until drivers are converted to use the new
interfaces (actually, converted back to use the _older_ interfaces)
which prohibit indirect configuration devices from receiving a softc
in their match routine that they can share with their attach routine.
Lets users over-ride with makeoptions COPTS="..." in kernel config files.
Leave `mandatory' flags (like -msoft-float which on m68k enforces no
FP in kernel) in CFLAGS.