ASoC: simple-card-utils: enable "label" on asoc_simple_card_parse_card_name

Current asoc_simple_card_parse_card_name() detects [prefix]name,
but in generally, we uses "label" for user visible names.
This patch enables it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>