[ALSA] unregister platform device again if probe was unsuccessful

This second one unregisters the platform device again when the probe is
unsuccesful for sound/drivers, sound/arm/sa11xx-uda1341.c and
sound/ppc/powermac.c. This gets them all.

Signed-off-by: Rene Herman <rene.herman@keyaccess.nl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>