pcm: iec958: set channel status bits according to rate and format

pcm: iec958: set channel status bits according to rate and format

This mimics snd_pcm_create_iec958_consumer in the kernel.

The rate and wordlength bits will only be modified if they are
set to "not indicated", which is now the default if no status
option is used.

This allows applications to override parameters determined from
the stream or implement channel status bits extensions without
needing to change pcm_iec958 code.

Signed-off-by: Matthias Reichl <hias@horus.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>