ALSA: emu10k1: fix capture buffer size confusion

ALSA: emu10k1: fix capture buffer size confusion

The buffer size register sets the size of the whole buffer, not just one
period. We actually handled it like that, except that the constraint was
set on the wrong parameter. The period size is implicitly constrained by
the buffer size and the fixed period count of 2.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230523200709.236059-2-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>