ASoC: simple_card_utils: tidyup file comment/define

simple_card_utils was created as simple_card_core in 1st prototype,
and current code still have it. Let's tidyup

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