peci: Constify struct peci_controller_ops

peci: Constify struct peci_controller_ops

As with most ops structs, we never modify it at runtime, and keeping
function pointers in read-only memory is generally a good thing
security-wise.

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20230327224315.11135-1-zev@bewilderbeest.net
Reviewed-by: Iwona Winiarska <iwona.winiarska@intel.com>
Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Link: https://lore.kernel.org/r/20230623142805.577612-1-iwona.winiarska@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>