ASoC: rsnd: tidyup rsnd_dma_request_channel()

This patch adds "char *name" to rsnd_dma_request_channel().
It is not yet used so far, but is preparation for
next "ASoC: rsnd: adjust disabled module" patch

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/878s3vk01q.wl-kuninori.morimoto.gx@renesas.com


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