sparc32: move smp ipi to method ops

I ended up renaming set_cpu_int to send_ipi to
be consistent all way around.
send_ipi was moved to the *_smp.c files so
we could call the relevant method direct,
without any _ops indirection.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>