ALSA: wss_lib: Fix resume on Yamaha OPL3-SAx

Yamaha OPL3-SAx chips don't resume properly when playback is running -
garbage is played after resume. Restoring the CS4231_PLAYBK_FORMAT register
last fixes the problem.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>