ASoC: simple-card-utils: rename asoc_simple_card_xxx() to asoc_simple_()

Current simple-card-utils is using asoc_simple_card_xxx() for each
function naming, but it is very verbose.
Thus it is easy to be over 80 char.
This patch renames it to asoc_simple_xxx().

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