Switch to DEFINE_SIMPLE_DEV_PM_OPS() so that the __maybe_unused can
be dropped from the suspend/resume callbacks.

While at it also drop the _wmi_ part from the callback names in preparation
for making lenovo-yogabook-wmi also work on the Android version of
the Yoga Book 1 which does not have a WMI interface to deal with toggling
the keyboard half between touch-keyboard and wacom-digitizer mode.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-7-hdegoede@redhat.com