[ALSA] ice1724 - Misc fixes for Prodigy192

- always set 256fs in SPDIF master clock mode
- disable deemphasis filter in AK4114 for Prodigy192

Signed-off-by: Pavel Hofman <dustin@seznam.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>