ASoC: soc-core: self contained soc_bind_aux_dev()

Current soc_bind_aux_dev() implementation is very half,
thus it is very unreadable.

	for_each_card_pre_auxs(xxx) {
=>		ret = soc_bind_aux_dev(xxx);
		...
	}

This patch does all for_each_xxx() under soc_bind_aux_dev(),
and makes it to self contained.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87tv9sor1b.wl-kuninori.morimoto.gx@renesas.com


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