SET_SYSTEM_SLEEP_PM_OPS() is deprecated as it requires explicit protection
against unused function warnings.  The new combination of pm_sleep_ptr()
and SYSTEM_SLEEP_PM_OPS() allows the compiler to see the functions,
thus suppressing the warning, but still allowing the unused code to be
removed. Thus also drop the __maybe_unused markings.

In this case we also have a .poweroff_late() callback. Whilst not
strictly necessary, to future proof against relaxation of the protection
of the main driver.pm = pm_sleep_ptr() protect this pointer with
pm_sleep_ptr() as would be done if the LATE_SYSTEM_SLEEP_PM_OPS()
macro were used to set it.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230114171620.42891-13-jic23@kernel.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>