drivers/macintosh: Make wf_control_ops and wf_pid_param const

Make wf_control_ops const as they are only stored in the ops field of a
wf_control structure, which is const.
Make wf_pid_param const as they are only used during a copy operation.
Done using Coccinelle.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>