ALSA: emu10k1: fix PCM playback cache and interrupt handling

ALSA: emu10k1: fix PCM playback cache and interrupt handling

The cache causes a fixed delay regardless of stream parameters.
Consequently, all that "cache invalidate size" calculation stuff was
garbage (which can be traced right back to Creative's OSS driver).

This also removes the definitions of registers CD1..CDF, because they
are accessed only relative to CD0 anyway.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230517174256.3657060-5-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>