snd-aoa: remove commented out Kconfig entry

config SND_AOA_TOPAZ has been commented out since it was added five
years ago with commit f3d9478b ("[...] add snd-aoa"). There's no
indication why it's commented out. It might as well be removed.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>