ALSA: emu10k1: fix PCM playback buffer size constraints

ALSA: emu10k1: fix PCM playback buffer size constraints

The period_bytes_min parameter and the buffer_bytes minimum constraint
made no sense at all, as they didn't reflect any hardware limitation.
Instead, apply a frame-based period_size minimum constraint, which is
derived from the cache size (it would be actually possible to go below
that, but it would require special handling, and it would be practically
impossible to keep up with the IRQ rate anyway).

Sync up the constraints of the EFX playback with those of the regular
playback, as there is no reason for them to diverge.

N.b., the maximum buffer size is actually arbitrary - the hardware could
go waay beyond 128 KiB.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230518092224.3696958-9-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>