The current hardware has up to 4 converters. Save little space.
The limit 8 is enough even for a more improved hardware.
Signed-off-by: NJaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220923082236.61024-1-perex@perex.czSigned-off-by: NTakashi Iwai <tiwai@suse.de>