ASoC: rsnd: add rsnd_parse_connect_common() and remove complex macro

Current rsnd driver is using complex macro to parse DAI connection.
This patch adds new rsnd_parse_connect_common() and replace current
macro to it.
This is prepare for multi channel support

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