ASoC: rsnd: modify rsnd_adg_ssi_ws_timing_gen2() parameter

rsnd_adg_ssi_ws_timing_gen2() returns SSI WS timing,
and it used "mod" as parameter.
but, this "mod" is sometimes not ssi mod.
Get SSI mod from rsnd_dai_stream

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