ALSA: hda - More robustify the power-up/down sequence

Check the power_transition up/down state instead of boolean bit, so
that the power-up sequence can cancel the pending power-down work
properly.  Also, by moving cancel_delayed_work_sync() before the
actual power-up sequence, make sure that the delayed power-down is
completed.

Signed-off-by: Takashi Iwai <tiwai@suse.de>