ALSA: oxygen: export oxygen_update_dac_routing symbol

When the user switches the output from stereo to multichannel
or vice versa, the driver needs to update the channel routing.
Instead of creating additional subroutines, I better export existing
oxygen_update_dac_routing symbol from the oxygen mixer
and call this function. It calls model.adjust_dac_routing()
and my function does the work.
Signed-off-by: Roman Volkov <v1ron@mail.ru>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

sound/pci/oxygen/oxygen_mixer.c

@@ -190,6 +190,7 @@ void oxygen_update_dac_routing(struct oxygen *chip)
 	if (chip->model.update_center_lfe_mix)
 		chip->model.update_center_lfe_mix(chip, chip->dac_routing > 2);
 }
+EXPORT_SYMBOL(oxygen_update_dac_routing);
 
 static int upmix_put(struct snd_kcontrol *ctl, struct snd_ctl_elem_value *value)
 {