ASoC: rsnd: run rsnd_path_init() when probe() timing

Current rsnd SSIU/SSI/SCU/SRU path is set
when playback/capture starts up.
But it is meaningless method, since the path is based
on platform and can be set in probe() timing.
This patch sets the path on probe() timing.

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