ALSA: emu10k1: pass raw FX send config to snd_emu10k1_pcm_init_voice()

... instead of passing in a high-level mixer struct. Let the
higher-level functions handle the differences between the voice types.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230523104612.198884-2-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>