ASoC: rsnd: use 32bit TDM width as default

commit fb2815f4 ("ASoC: rsnd: add support for 16/24 bit slot widths")
added TDM width check, and return error if it was not 16/24/32 bit.
But it is too strict. This patch uses 32bit same as default.

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