ALSA: emu10k1: fixup DSP defines

ALSA: emu10k1: fixup DSP defines

Firstly, fix the distribution between public and private headers.
Otherwise, some of the already public macros wouldn't actually work, and
the SNDRV_EMU10K1_IOCTL_DBG_READ result for Audigy would be useless.

Secondly, add condition code registers for Audigy. These are just
aliases for selected constant registers, and thus are generation-
specific. At least A_CC_REG_ZERO is actually correct ...

Finally, shuffle around some defines to more logical places while at it,
and fix up some more comments.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230422161021.1143903-7-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>