(currently only CD-ROM drives on i386). The sys/dev/scsipi system provides 2
busses to which devices can attach (scsibus and atapibus). This needed to
change some include files and structure names in the low level scsi drivers.
* 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.
* Add cast to hardclock when it's used directly as an interrupt handler.
* Add a null-interrupt-establish function, to avoid int vs void lint
in pica/dev/dma.c.
* fix include in pica/include/pccons.h to work with "standard"
kernel-compile include path.
bouyer