pm: device: store power state in all scenarios

Update the internal power state tracking for `PM_DEVICE_ACTION_TURN_ON`
and `PM_DEVICE_ACTION_TURN_OFF` even when the transition function fails.
Just because the driver couldn't perform some action does not mean the
device is still powered/unpowered.

Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>