ALSA: emu10k1: use high-level I/O functions also during init

... and also use more pre-defined constants on the way (some of which
required adjustment).

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>

Link: https://lore.kernel.org/r/20230422161021.1143967-1-oswald.buddenhagen@gmx.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>