m68k: Remove five unused headers

There are five entirely unused headers in arch/m68k/include/asm. Nothing
includes these headers. And a few tests found no hits for the things
they provide (which makes sense).

MC68332.h, mac_mouse.h, and mcfmbus.h are all unused since at least
v2.6.12-rc2 (I didn't bother looking further back than that).

apollodma.h is unused since v2.6.19: commit
2ed0ce5 ("m68k/Apollo: Remove obsolete
arch/m68k/apollo/dma.c") removed the last file interested in that
header.

And everything interested in <asm/sbus.h> was removed in the v2.6.28
release cycle. The last occurrence of "sbus.h" was deleted with commit
0c0db98 ("sparc: Remove
Documentation/sparc/sbus_drivers.txt"). I'm not sure whether anything
relevant for m68k was included in v2.6.27, but it doesn't really matter.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Acked-by: Greg Ungerer<gerg@uclinux.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>