ASoC: simple-card: tidyup use priv in parameter

priv has many information about simple-card driver.
Using it becomes easy to extend feature.
This patch gets dev from priv as 1st step

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