ALSA: Avoid endless sleep after disconnect

commit 0914f7961babbf28aaa2f19b453951fb4841c03f upstream.

When disconnect callback is called, each component should wake up
sleepers and check card->shutdown flag for avoiding the endless sleep
blocking the proper resource release.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>