ALSA: cs46xx - Fix minimum period size

commit 6148b130eb84edc76e4fa88da1877b27be6c2f06 upstream.

Fix minimum period size for cs46xx cards. This fixes a problem in the
case where neither a period size nor a buffer size is passed to ALSA;
this is the case in Audacious, OpenAL, and others.

Signed-off-by: Sophie Hamilton <kernel@theblob.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>