The HD-audio driver artificially calls the suspend and the resume code
path in the VGA switcheroo state changes.  When a machine goes to
suspend, it tries to suspend the device again, and it stalls at
snd_power_wait().

This patch adds checks whether the devices were already in (forced)
suspend in PM callbacks for avoiding the doubly suspend.
Reported-by: Daniel J Blueman <daniel@quora.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>