ASoC: soc-ops: use snd_soc_card_get_kcontrol() at snd_soc_limit_volume()

snd_soc_limit_volume() is finding snd_kcontrol by using original coding,
but we already have snd_soc_card_get_kcontrol().
Let's use existing function.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87y2y3afgd.wl-kuninori.morimoto.gx@renesas.com


Signed-off-by: Mark Brown <broonie@kernel.org>