ALSA: hda - Disable sticky PCM stream assignment for AD codecs

The sticky PCM stream assignment introduced in 2.6.36 kernel seems
causing problems on AD codecs.  At some time later, the streaming no
longer works by unknown reason.  A simple workaround is to disable
sticky-assignment for these codecs.

Tested-by: Vasily Khoruzhick <anarsoul@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>