[PATCH] m68k pt_regs fixes, part 2

Fallout from previous patch:
 - actually add include/asm-m68k/irq_regs.h
 - missed the prototype of sun3_sched_init()

NB: git diff without argumentgs sucks when you've added
some files...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>