ALSA: aoa: onyx: Update IEC958 sample-rate status for PCM playback

ALSA: aoa: onyx: Update IEC958 sample-rate status for PCM playback

onyx_prepare() accepts 32/44.1/48 kHz PCM playback, but it leaves the
Onyx IEC958 sample-rate status bits at the driver's initial 44.1 kHz
setting in DIG_INFO3. As a result, 32 kHz and 48 kHz PCM streams
advertise a stale IEC958 sample rate unless userspace rewrites IEC958
Playback Default first.

Update only the consumer sample-frequency bits in DIG_INFO3 from the PCM
runtime during prepare, resolving the long-standing FIXME in the PCM
playback path while leaving the other user-controlled IEC958 status bits
unchanged.

Mark IEC958 Playback Default as volatile as well, since prepare() now
changes the exposed register contents outside the control put callback.

Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
Link: https://patch.msgid.link/20260403-onyx-spdif-pcm-rate-v1-1-dcfaf931cf83@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>