Move the trap/vector initialization for MPC6xx ports to mpc6xx_machdep.c
Also move softnet, install_extintr, mapiodev, kvtop. Add common BAT
initialization code.
Add user Altivec support.
Fix calls to OF_call_method in macppc/macppc/machdep.c.
Use ci_fpuproc in cpu_info instead of separate fpuproc.
Add separate syscall.c and defined __HAVE_SYSCALL_INTERN.