ASoC: SOF: compress: return the configured codec from get_params

ASoC: SOF: compress: return the configured codec from get_params

The SOF compressed offload path accepts codec parameters in
sof_compr_set_params() and forwards them to firmware as
extended data in the SOF IPC stream params message.

However, sof_compr_get_params() still returns success without
filling the snd_codec structure. Since the compress core allocates
that structure zeroed and copies it back to userspace on success,
SNDRV_COMPRESS_GET_PARAMS returns an all-zero codec description
even after the stream has been configured successfully.

The stale TODO in this callback conflates get_params() with capability
discovery. Supported codec enumeration belongs in get_caps() and
get_codec_caps(). get_params() should report the current codec settings.

Cache the codec accepted by sof_compr_set_params() in the per-stream SOF
compress state and return it from sof_compr_get_params().

Fixes: 6324cf901e14 ("ASoC: SOF: compr: Add compress ops implementation")
Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
Link: https://patch.msgid.link/20260325-sof-compr-get-params-v1-1-0758815f13c7@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>