ASoC: rsnd: dma.c: tidyup rsnd_dma_probe()

This patch tidyups rsnd_dma_probe(), but there is no effect.

This is prepare for Gen4 support.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87r0va5elq.wl-kuninori.morimoto.gx@renesas.com


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