ASoC: simple-scu-card: code sync: rename asoc_simple_card_priv

simple sound card family are using very similar style, but because of its
historical reason, there are small differences. For example pointer style,
function name, caller postion etc...
This patch synchronized simple card style to other simple card family

This patch renames asoc_simple_card_priv to simple_card_data,
same as other simple card family.

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