* add prototypes to <dma.h> for the per-device dma-setup functions.
* MachEmptyWriteBuffer() -> wbflush(). Also #include <bus.h>,
so that wbflush() expants to the locore callback vector entrypoint.
* include <mips/locore.h> where callbacks into locore are made, to get
prototypes in scope. Cast calls appropriately.
* include <mips/cpuregs.h>, not the old Sprite-derived <machine/machConst.h>.
machConst.h is deprecated.
* dk_establish() must return void, not int.
- split softc size and match/attach out from cfdriver into
a new struct cfattach.
- new "attach" directive for files.*. May specify the name of
the cfattach structure, so that devices may be easily attached
to parents with different autoconfiguration semantics.
